+ template < typename T >
+ struct check {};
+
+ typedef check<void> single_type;
+ typedef check<check<void>> double_type;
+ typedef check<check<check<void>>> triple_type;
+ typedef check<check<check<check<void>>>> quadruple_type;
+
+ }
+
+ namespace test_decltype
+ {
+
+ int
+ f()
+ {
+ int a = 1;
+ decltype(a) b = 2;
+ return a + b;
+ }
+
+ }
+
+ namespace test_type_deduction
+ {
+
+ template < typename T1, typename T2 >
+ struct is_same
+ {
+ static const bool value = false;
+ };
+
+ template < typename T >
+ struct is_same<T, T>
+ {
+ static const bool value = true;
+ };
+
+ template < typename T1, typename T2 >
+ auto
+ add(T1 a1, T2 a2) -> decltype(a1 + a2)
+ {
+ return a1 + a2;
+ }
+
+ int
+ test(const int c, volatile int v)
+ {
+ static_assert(is_same<int, decltype(0)>::value == true, "");
+ static_assert(is_same<int, decltype(c)>::value == false, "");
+ static_assert(is_same<int, decltype(v)>::value == false, "");
+ auto ac = c;
+ auto av = v;
+ auto sumi = ac + av + 'x';
+ auto sumf = ac + av + 1.0;
+ static_assert(is_same<int, decltype(ac)>::value == true, "");
+ static_assert(is_same<int, decltype(av)>::value == true, "");
+ static_assert(is_same<int, decltype(sumi)>::value == true, "");
+ static_assert(is_same<int, decltype(sumf)>::value == false, "");
+ static_assert(is_same<int, decltype(add(c, v))>::value == true, "");
+ return (sumf > 0.0) ? sumi : add(c, v);
+ }
+
+ }
+
+ namespace test_noexcept
+ {
+
+ int f() { return 0; }
+ int g() noexcept { return 0; }
+
+ static_assert(noexcept(f()) == false, "");
+ static_assert(noexcept(g()) == true, "");
+
+ }
+
+ namespace test_constexpr
+ {
+
+ template < typename CharT >
+ unsigned long constexpr
+ strlen_c_r(const CharT *const s, const unsigned long acc) noexcept
+ {
+ return *s ? strlen_c_r(s + 1, acc + 1) : acc;
+ }
+
+ template < typename CharT >
+ unsigned long constexpr
+ strlen_c(const CharT *const s) noexcept
+ {
+ return strlen_c_r(s, 0UL);
+ }
+
+ static_assert(strlen_c("") == 0UL, "");
+ static_assert(strlen_c("1") == 1UL, "");
+ static_assert(strlen_c("example") == 7UL, "");
+ static_assert(strlen_c("another\0example") == 7UL, "");
+
+ }
+
+ namespace test_rvalue_references
+ {
+
+ template < int N >
+ struct answer
+ {
+ static constexpr int value = N;
+ };
+
+ answer<1> f(int&) { return answer<1>(); }
+ answer<2> f(const int&) { return answer<2>(); }
+ answer<3> f(int&&) { return answer<3>(); }
+
+ void
+ test()
+ {
+ int i = 0;
+ const int c = 0;
+ static_assert(decltype(f(i))::value == 1, "");
+ static_assert(decltype(f(c))::value == 2, "");
+ static_assert(decltype(f(0))::value == 3, "");
+ }
+
+ }
+
+ namespace test_uniform_initialization
+ {
+
+ struct test
+ {
+ static const int zero {};
+ static const int one {1};
+ };
+
+ static_assert(test::zero == 0, "");
+ static_assert(test::one == 1, "");
+
+ }
+
+ namespace test_lambdas
+ {
+
+ void
+ test1()
+ {
+ auto lambda1 = [](){};
+ auto lambda2 = lambda1;
+ lambda1();
+ lambda2();
+ }
+
+ int
+ test2()
+ {
+ auto a = [](int i, int j){ return i + j; }(1, 2);
+ auto b = []() -> int { return '0'; }();
+ auto c = [=](){ return a + b; }();
+ auto d = [&](){ return c; }();
+ auto e = [a, &b](int x) mutable {
+ const auto identity = [](int y){ return y; };
+ for (auto i = 0; i < a; ++i)
+ a += b--;
+ return x + identity(a + b);
+ }(0);
+ return a + b + c + d + e;
+ }
+
+ int
+ test3()
+ {
+ const auto nullary = [](){ return 0; };
+ const auto unary = [](int x){ return x; };
+ using nullary_t = decltype(nullary);
+ using unary_t = decltype(unary);
+ const auto higher1st = [](nullary_t f){ return f(); };
+ const auto higher2nd = [unary](nullary_t f1){
+ return [unary, f1](unary_t f2){ return f2(unary(f1())); };
+ };
+ return higher1st(nullary) + higher2nd(nullary)(unary);
+ }
+
+ }
+
+ namespace test_variadic_templates
+ {
+
+ template <int...>
+ struct sum;
+
+ template <int N0, int... N1toN>
+ struct sum<N0, N1toN...>
+ {
+ static constexpr auto value = N0 + sum<N1toN...>::value;
+ };
+
+ template <>
+ struct sum<>
+ {
+ static constexpr auto value = 0;
+ };
+
+ static_assert(sum<>::value == 0, "");
+ static_assert(sum<1>::value == 1, "");
+ static_assert(sum<23>::value == 23, "");
+ static_assert(sum<1, 2>::value == 3, "");
+ static_assert(sum<5, 5, 11>::value == 21, "");
+ static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, "");
+
+ }
+
+ // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae
+ // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function
+ // because of this.
+ namespace test_template_alias_sfinae
+ {
+
+ struct foo {};
+
+ template<typename T>
+ using member = typename T::member_type;
+
+ template<typename T>
+ void func(...) {}
+
+ template<typename T>
+ void func(member<T>*) {}
+
+ void test();
+
+ void test() { func<foo>(0); }
+
+ }
+
+} // namespace cxx11
+
+#endif // __cplusplus >= 201103L
+
+
+
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+ ax_cv_cxx_compile_cxx11=yes
+else
+ ax_cv_cxx_compile_cxx11=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_cxx_compile_cxx11" >&5
+$as_echo "$ax_cv_cxx_compile_cxx11" >&6; }
+ if test x$ax_cv_cxx_compile_cxx11 = xyes; then
+ ac_success=yes
+ fi
+
+ if test x$ac_success = xno; then
+ for alternative in ${ax_cxx_compile_alternatives}; do
+ switch="-std=gnu++${alternative}"
+ cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh`
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5
+$as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; }
+if eval \${$cachevar+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ ac_save_CXX="$CXX"
+ CXX="$CXX $switch"
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+
+// If the compiler admits that it is not ready for C++11, why torture it?
+// Hopefully, this will speed up the test.
+
+#ifndef __cplusplus
+
+#error "This is not a C++ compiler"
+
+#elif __cplusplus < 201103L
+
+#error "This is not a C++11 compiler"
+
+#else
+
+namespace cxx11
+{
+
+ namespace test_static_assert
+ {
+
+ template <typename T>
+ struct check
+ {
+ static_assert(sizeof(int) <= sizeof(T), "not big enough");
+ };
+
+ }
+
+ namespace test_final_override
+ {
+
+ struct Base
+ {
+ virtual ~Base() {}
+ virtual void f() {}
+ };
+
+ struct Derived : public Base
+ {
+ virtual ~Derived() override {}
+ virtual void f() override {}
+ };
+
+ }
+
+ namespace test_double_right_angle_brackets
+ {
+
+ template < typename T >
+ struct check {};
+
+ typedef check<void> single_type;
+ typedef check<check<void>> double_type;
+ typedef check<check<check<void>>> triple_type;
+ typedef check<check<check<check<void>>>> quadruple_type;
+
+ }
+
+ namespace test_decltype
+ {
+
+ int
+ f()
+ {
+ int a = 1;
+ decltype(a) b = 2;
+ return a + b;
+ }
+
+ }
+
+ namespace test_type_deduction
+ {
+
+ template < typename T1, typename T2 >
+ struct is_same
+ {
+ static const bool value = false;
+ };
+
+ template < typename T >
+ struct is_same<T, T>
+ {
+ static const bool value = true;
+ };
+
+ template < typename T1, typename T2 >
+ auto
+ add(T1 a1, T2 a2) -> decltype(a1 + a2)
+ {
+ return a1 + a2;
+ }
+
+ int
+ test(const int c, volatile int v)
+ {
+ static_assert(is_same<int, decltype(0)>::value == true, "");
+ static_assert(is_same<int, decltype(c)>::value == false, "");
+ static_assert(is_same<int, decltype(v)>::value == false, "");
+ auto ac = c;
+ auto av = v;
+ auto sumi = ac + av + 'x';
+ auto sumf = ac + av + 1.0;
+ static_assert(is_same<int, decltype(ac)>::value == true, "");
+ static_assert(is_same<int, decltype(av)>::value == true, "");
+ static_assert(is_same<int, decltype(sumi)>::value == true, "");
+ static_assert(is_same<int, decltype(sumf)>::value == false, "");
+ static_assert(is_same<int, decltype(add(c, v))>::value == true, "");
+ return (sumf > 0.0) ? sumi : add(c, v);
+ }
+
+ }
+
+ namespace test_noexcept
+ {
+
+ int f() { return 0; }
+ int g() noexcept { return 0; }
+
+ static_assert(noexcept(f()) == false, "");
+ static_assert(noexcept(g()) == true, "");
+
+ }
+
+ namespace test_constexpr
+ {
+
+ template < typename CharT >
+ unsigned long constexpr
+ strlen_c_r(const CharT *const s, const unsigned long acc) noexcept
+ {
+ return *s ? strlen_c_r(s + 1, acc + 1) : acc;
+ }
+
+ template < typename CharT >
+ unsigned long constexpr
+ strlen_c(const CharT *const s) noexcept
+ {
+ return strlen_c_r(s, 0UL);
+ }
+
+ static_assert(strlen_c("") == 0UL, "");
+ static_assert(strlen_c("1") == 1UL, "");
+ static_assert(strlen_c("example") == 7UL, "");
+ static_assert(strlen_c("another\0example") == 7UL, "");
+
+ }
+
+ namespace test_rvalue_references
+ {
+
+ template < int N >
+ struct answer
+ {
+ static constexpr int value = N;
+ };
+
+ answer<1> f(int&) { return answer<1>(); }
+ answer<2> f(const int&) { return answer<2>(); }
+ answer<3> f(int&&) { return answer<3>(); }
+
+ void
+ test()
+ {
+ int i = 0;
+ const int c = 0;
+ static_assert(decltype(f(i))::value == 1, "");
+ static_assert(decltype(f(c))::value == 2, "");
+ static_assert(decltype(f(0))::value == 3, "");
+ }
+
+ }
+
+ namespace test_uniform_initialization
+ {
+
+ struct test
+ {
+ static const int zero {};
+ static const int one {1};
+ };
+
+ static_assert(test::zero == 0, "");
+ static_assert(test::one == 1, "");
+
+ }
+
+ namespace test_lambdas
+ {
+
+ void
+ test1()
+ {
+ auto lambda1 = [](){};
+ auto lambda2 = lambda1;
+ lambda1();
+ lambda2();
+ }
+
+ int
+ test2()
+ {
+ auto a = [](int i, int j){ return i + j; }(1, 2);
+ auto b = []() -> int { return '0'; }();
+ auto c = [=](){ return a + b; }();
+ auto d = [&](){ return c; }();
+ auto e = [a, &b](int x) mutable {
+ const auto identity = [](int y){ return y; };
+ for (auto i = 0; i < a; ++i)
+ a += b--;
+ return x + identity(a + b);
+ }(0);
+ return a + b + c + d + e;
+ }
+
+ int
+ test3()
+ {
+ const auto nullary = [](){ return 0; };
+ const auto unary = [](int x){ return x; };
+ using nullary_t = decltype(nullary);
+ using unary_t = decltype(unary);
+ const auto higher1st = [](nullary_t f){ return f(); };
+ const auto higher2nd = [unary](nullary_t f1){
+ return [unary, f1](unary_t f2){ return f2(unary(f1())); };
+ };
+ return higher1st(nullary) + higher2nd(nullary)(unary);
+ }
+
+ }
+
+ namespace test_variadic_templates
+ {
+
+ template <int...>
+ struct sum;
+
+ template <int N0, int... N1toN>
+ struct sum<N0, N1toN...>
+ {
+ static constexpr auto value = N0 + sum<N1toN...>::value;
+ };
+
+ template <>
+ struct sum<>
+ {
+ static constexpr auto value = 0;
+ };
+
+ static_assert(sum<>::value == 0, "");
+ static_assert(sum<1>::value == 1, "");
+ static_assert(sum<23>::value == 23, "");
+ static_assert(sum<1, 2>::value == 3, "");
+ static_assert(sum<5, 5, 11>::value == 21, "");
+ static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, "");
+
+ }
+
+ // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae
+ // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function
+ // because of this.
+ namespace test_template_alias_sfinae
+ {
+
+ struct foo {};
+
+ template<typename T>
+ using member = typename T::member_type;
+
+ template<typename T>
+ void func(...) {}
+
+ template<typename T>
+ void func(member<T>*) {}
+
+ void test();
+
+ void test() { func<foo>(0); }
+
+ }
+
+} // namespace cxx11
+
+#endif // __cplusplus >= 201103L
+
+
+
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+ eval $cachevar=yes
+else
+ eval $cachevar=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ CXX="$ac_save_CXX"
+fi
+eval ac_res=\$$cachevar
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+ if eval test x\$$cachevar = xyes; then
+ CXX="$CXX $switch"
+ if test -n "$CXXCPP" ; then
+ CXXCPP="$CXXCPP $switch"
+ fi
+ ac_success=yes
+ break
+ fi
+ done
+ fi
+
+ if test x$ac_success = xno; then
+ for alternative in ${ax_cxx_compile_alternatives}; do
+ for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do
+ cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_$switch" | $as_tr_sh`
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5
+$as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; }
+if eval \${$cachevar+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ ac_save_CXX="$CXX"
+ CXX="$CXX $switch"
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+
+// If the compiler admits that it is not ready for C++11, why torture it?
+// Hopefully, this will speed up the test.
+
+#ifndef __cplusplus
+
+#error "This is not a C++ compiler"
+
+#elif __cplusplus < 201103L
+
+#error "This is not a C++11 compiler"
+
+#else
+
+namespace cxx11
+{
+
+ namespace test_static_assert
+ {
+
+ template <typename T>
+ struct check
+ {
+ static_assert(sizeof(int) <= sizeof(T), "not big enough");
+ };
+
+ }
+
+ namespace test_final_override
+ {
+
+ struct Base
+ {
+ virtual ~Base() {}
+ virtual void f() {}
+ };
+
+ struct Derived : public Base
+ {
+ virtual ~Derived() override {}
+ virtual void f() override {}
+ };
+
+ }
+
+ namespace test_double_right_angle_brackets
+ {
+
+ template < typename T >
+ struct check {};
+
+ typedef check<void> single_type;
+ typedef check<check<void>> double_type;
+ typedef check<check<check<void>>> triple_type;
+ typedef check<check<check<check<void>>>> quadruple_type;
+
+ }
+
+ namespace test_decltype
+ {
+
+ int
+ f()
+ {
+ int a = 1;
+ decltype(a) b = 2;
+ return a + b;
+ }
+
+ }
+
+ namespace test_type_deduction
+ {
+
+ template < typename T1, typename T2 >
+ struct is_same
+ {
+ static const bool value = false;
+ };
+
+ template < typename T >
+ struct is_same<T, T>
+ {
+ static const bool value = true;
+ };
+
+ template < typename T1, typename T2 >
+ auto
+ add(T1 a1, T2 a2) -> decltype(a1 + a2)
+ {
+ return a1 + a2;
+ }
+
+ int
+ test(const int c, volatile int v)
+ {
+ static_assert(is_same<int, decltype(0)>::value == true, "");
+ static_assert(is_same<int, decltype(c)>::value == false, "");
+ static_assert(is_same<int, decltype(v)>::value == false, "");
+ auto ac = c;
+ auto av = v;
+ auto sumi = ac + av + 'x';
+ auto sumf = ac + av + 1.0;
+ static_assert(is_same<int, decltype(ac)>::value == true, "");
+ static_assert(is_same<int, decltype(av)>::value == true, "");
+ static_assert(is_same<int, decltype(sumi)>::value == true, "");
+ static_assert(is_same<int, decltype(sumf)>::value == false, "");
+ static_assert(is_same<int, decltype(add(c, v))>::value == true, "");
+ return (sumf > 0.0) ? sumi : add(c, v);
+ }
+
+ }
+
+ namespace test_noexcept
+ {
+
+ int f() { return 0; }
+ int g() noexcept { return 0; }
+
+ static_assert(noexcept(f()) == false, "");
+ static_assert(noexcept(g()) == true, "");
+
+ }
+
+ namespace test_constexpr
+ {
+
+ template < typename CharT >
+ unsigned long constexpr
+ strlen_c_r(const CharT *const s, const unsigned long acc) noexcept
+ {
+ return *s ? strlen_c_r(s + 1, acc + 1) : acc;
+ }
+
+ template < typename CharT >
+ unsigned long constexpr
+ strlen_c(const CharT *const s) noexcept
+ {
+ return strlen_c_r(s, 0UL);
+ }
+
+ static_assert(strlen_c("") == 0UL, "");
+ static_assert(strlen_c("1") == 1UL, "");
+ static_assert(strlen_c("example") == 7UL, "");
+ static_assert(strlen_c("another\0example") == 7UL, "");
+
+ }
+
+ namespace test_rvalue_references
+ {
+
+ template < int N >
+ struct answer
+ {
+ static constexpr int value = N;
+ };
+
+ answer<1> f(int&) { return answer<1>(); }
+ answer<2> f(const int&) { return answer<2>(); }
+ answer<3> f(int&&) { return answer<3>(); }
+
+ void
+ test()
+ {
+ int i = 0;
+ const int c = 0;
+ static_assert(decltype(f(i))::value == 1, "");
+ static_assert(decltype(f(c))::value == 2, "");
+ static_assert(decltype(f(0))::value == 3, "");
+ }
+
+ }
+
+ namespace test_uniform_initialization
+ {
+
+ struct test
+ {
+ static const int zero {};
+ static const int one {1};
+ };
+
+ static_assert(test::zero == 0, "");
+ static_assert(test::one == 1, "");
+
+ }
+
+ namespace test_lambdas
+ {
+
+ void
+ test1()
+ {
+ auto lambda1 = [](){};
+ auto lambda2 = lambda1;
+ lambda1();
+ lambda2();
+ }
+
+ int
+ test2()
+ {
+ auto a = [](int i, int j){ return i + j; }(1, 2);
+ auto b = []() -> int { return '0'; }();
+ auto c = [=](){ return a + b; }();
+ auto d = [&](){ return c; }();
+ auto e = [a, &b](int x) mutable {
+ const auto identity = [](int y){ return y; };
+ for (auto i = 0; i < a; ++i)
+ a += b--;
+ return x + identity(a + b);
+ }(0);
+ return a + b + c + d + e;
+ }
+
+ int
+ test3()
+ {
+ const auto nullary = [](){ return 0; };
+ const auto unary = [](int x){ return x; };
+ using nullary_t = decltype(nullary);
+ using unary_t = decltype(unary);
+ const auto higher1st = [](nullary_t f){ return f(); };
+ const auto higher2nd = [unary](nullary_t f1){
+ return [unary, f1](unary_t f2){ return f2(unary(f1())); };
+ };
+ return higher1st(nullary) + higher2nd(nullary)(unary);
+ }
+
+ }
+
+ namespace test_variadic_templates
+ {
+
+ template <int...>
+ struct sum;
+
+ template <int N0, int... N1toN>
+ struct sum<N0, N1toN...>
+ {
+ static constexpr auto value = N0 + sum<N1toN...>::value;
+ };
+
+ template <>
+ struct sum<>
+ {
+ static constexpr auto value = 0;
+ };
+
+ static_assert(sum<>::value == 0, "");
+ static_assert(sum<1>::value == 1, "");
+ static_assert(sum<23>::value == 23, "");
+ static_assert(sum<1, 2>::value == 3, "");
+ static_assert(sum<5, 5, 11>::value == 21, "");
+ static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, "");
+
+ }
+
+ // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae
+ // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function
+ // because of this.
+ namespace test_template_alias_sfinae
+ {
+
+ struct foo {};
+
+ template<typename T>
+ using member = typename T::member_type;
+
+ template<typename T>
+ void func(...) {}
+
+ template<typename T>
+ void func(member<T>*) {}
+
+ void test();
+
+ void test() { func<foo>(0); }
+
+ }
+
+} // namespace cxx11
+
+#endif // __cplusplus >= 201103L
+
+
+
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+ eval $cachevar=yes
+else
+ eval $cachevar=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ CXX="$ac_save_CXX"
+fi
+eval ac_res=\$$cachevar
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+ if eval test x\$$cachevar = xyes; then
+ CXX="$CXX $switch"
+ if test -n "$CXXCPP" ; then
+ CXXCPP="$CXXCPP $switch"
+ fi
+ ac_success=yes
+ break
+ fi
+ done
+ if test x$ac_success = xyes; then
+ break
+ fi
+ done
+ fi
+
+ ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ if test x$ax_cxx_compile_cxx11_required = xtrue; then
+ if test x$ac_success = xno; then
+ as_fn_error $? "*** A compiler with support for C++11 language features is required." "$LINENO" 5
+ fi
+ fi
+ if test x$ac_success = xno; then
+ HAVE_CXX11=0
+ { $as_echo "$as_me:${as_lineno-$LINENO}: No compiler with C++11 support was found" >&5
+$as_echo "$as_me: No compiler with C++11 support was found" >&6;}
+ else
+ HAVE_CXX11=1
+
+$as_echo "#define HAVE_CXX11 1" >>confdefs.h
+
+ fi
+
+
+
+ if test "${build}" != "${host}"; then
+ ax_cxx_compile_alternatives="11 0x" ax_cxx_compile_cxx11_required=true
+ ac_ext=cpp
+ac_cpp='$CXXCPP $CPPFLAGS'
+ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
+ ac_success=no
+ ax_cv_cxx_compile_cxx11_orig_cxx="$CXX"
+ ax_cv_cxx_compile_cxx11_orig_cxxflags="$CXXFLAGS"
+ ax_cv_cxx_compile_cxx11_orig_cppflags="$CPPFLAGS"
+ CXX="$CXX_FOR_BUILD"
+ CXXFLAGS="$CXXFLAGS_FOR_BUILD"
+ CPPFLAGS="$CPPFLAGS_FOR_BUILD"
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features by default" >&5
+$as_echo_n "checking whether $CXX supports C++11 features by default... " >&6; }
+if ${ax_cv_cxx_compile_cxx11_FOR_BUILD+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+
+// If the compiler admits that it is not ready for C++11, why torture it?
+// Hopefully, this will speed up the test.
+
+#ifndef __cplusplus
+
+#error "This is not a C++ compiler"
+
+#elif __cplusplus < 201103L
+
+#error "This is not a C++11 compiler"
+
+#else
+
+namespace cxx11
+{
+
+ namespace test_static_assert
+ {
+
+ template <typename T>
+ struct check
+ {
+ static_assert(sizeof(int) <= sizeof(T), "not big enough");
+ };
+
+ }
+
+ namespace test_final_override
+ {
+
+ struct Base
+ {
+ virtual ~Base() {}
+ virtual void f() {}
+ };
+
+ struct Derived : public Base
+ {
+ virtual ~Derived() override {}
+ virtual void f() override {}
+ };
+
+ }
+
+ namespace test_double_right_angle_brackets
+ {
+
+ template < typename T >
+ struct check {};
+
+ typedef check<void> single_type;
+ typedef check<check<void>> double_type;
+ typedef check<check<check<void>>> triple_type;
+ typedef check<check<check<check<void>>>> quadruple_type;
+
+ }
+
+ namespace test_decltype
+ {
+
+ int
+ f()
+ {
+ int a = 1;
+ decltype(a) b = 2;
+ return a + b;
+ }
+
+ }
+
+ namespace test_type_deduction
+ {
+
+ template < typename T1, typename T2 >
+ struct is_same
+ {
+ static const bool value = false;
+ };
+
+ template < typename T >
+ struct is_same<T, T>
+ {
+ static const bool value = true;
+ };
+
+ template < typename T1, typename T2 >
+ auto
+ add(T1 a1, T2 a2) -> decltype(a1 + a2)
+ {
+ return a1 + a2;
+ }
+
+ int
+ test(const int c, volatile int v)
+ {
+ static_assert(is_same<int, decltype(0)>::value == true, "");
+ static_assert(is_same<int, decltype(c)>::value == false, "");
+ static_assert(is_same<int, decltype(v)>::value == false, "");
+ auto ac = c;
+ auto av = v;
+ auto sumi = ac + av + 'x';
+ auto sumf = ac + av + 1.0;
+ static_assert(is_same<int, decltype(ac)>::value == true, "");
+ static_assert(is_same<int, decltype(av)>::value == true, "");
+ static_assert(is_same<int, decltype(sumi)>::value == true, "");
+ static_assert(is_same<int, decltype(sumf)>::value == false, "");
+ static_assert(is_same<int, decltype(add(c, v))>::value == true, "");
+ return (sumf > 0.0) ? sumi : add(c, v);
+ }
+
+ }
+
+ namespace test_noexcept
+ {
+
+ int f() { return 0; }
+ int g() noexcept { return 0; }
+
+ static_assert(noexcept(f()) == false, "");
+ static_assert(noexcept(g()) == true, "");
+
+ }
+
+ namespace test_constexpr
+ {
+
+ template < typename CharT >
+ unsigned long constexpr
+ strlen_c_r(const CharT *const s, const unsigned long acc) noexcept
+ {
+ return *s ? strlen_c_r(s + 1, acc + 1) : acc;
+ }
+
+ template < typename CharT >
+ unsigned long constexpr
+ strlen_c(const CharT *const s) noexcept
+ {
+ return strlen_c_r(s, 0UL);
+ }
+
+ static_assert(strlen_c("") == 0UL, "");
+ static_assert(strlen_c("1") == 1UL, "");
+ static_assert(strlen_c("example") == 7UL, "");
+ static_assert(strlen_c("another\0example") == 7UL, "");
+
+ }
+
+ namespace test_rvalue_references
+ {
+
+ template < int N >
+ struct answer
+ {
+ static constexpr int value = N;
+ };
+
+ answer<1> f(int&) { return answer<1>(); }
+ answer<2> f(const int&) { return answer<2>(); }
+ answer<3> f(int&&) { return answer<3>(); }
+
+ void
+ test()
+ {
+ int i = 0;
+ const int c = 0;
+ static_assert(decltype(f(i))::value == 1, "");
+ static_assert(decltype(f(c))::value == 2, "");
+ static_assert(decltype(f(0))::value == 3, "");
+ }
+
+ }
+
+ namespace test_uniform_initialization
+ {
+
+ struct test
+ {
+ static const int zero {};
+ static const int one {1};
+ };
+
+ static_assert(test::zero == 0, "");
+ static_assert(test::one == 1, "");
+
+ }
+
+ namespace test_lambdas
+ {
+
+ void
+ test1()
+ {
+ auto lambda1 = [](){};
+ auto lambda2 = lambda1;
+ lambda1();
+ lambda2();
+ }
+
+ int
+ test2()
+ {
+ auto a = [](int i, int j){ return i + j; }(1, 2);
+ auto b = []() -> int { return '0'; }();
+ auto c = [=](){ return a + b; }();
+ auto d = [&](){ return c; }();
+ auto e = [a, &b](int x) mutable {
+ const auto identity = [](int y){ return y; };
+ for (auto i = 0; i < a; ++i)
+ a += b--;
+ return x + identity(a + b);
+ }(0);
+ return a + b + c + d + e;
+ }
+
+ int
+ test3()
+ {
+ const auto nullary = [](){ return 0; };
+ const auto unary = [](int x){ return x; };
+ using nullary_t = decltype(nullary);
+ using unary_t = decltype(unary);
+ const auto higher1st = [](nullary_t f){ return f(); };
+ const auto higher2nd = [unary](nullary_t f1){
+ return [unary, f1](unary_t f2){ return f2(unary(f1())); };
+ };
+ return higher1st(nullary) + higher2nd(nullary)(unary);
+ }
+
+ }
+
+ namespace test_variadic_templates
+ {
+
+ template <int...>
+ struct sum;
+
+ template <int N0, int... N1toN>
+ struct sum<N0, N1toN...>
+ {
+ static constexpr auto value = N0 + sum<N1toN...>::value;
+ };
+
+ template <>
+ struct sum<>
+ {
+ static constexpr auto value = 0;
+ };
+
+ static_assert(sum<>::value == 0, "");
+ static_assert(sum<1>::value == 1, "");
+ static_assert(sum<23>::value == 23, "");
+ static_assert(sum<1, 2>::value == 3, "");
+ static_assert(sum<5, 5, 11>::value == 21, "");
+ static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, "");
+
+ }
+
+ // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae
+ // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function
+ // because of this.
+ namespace test_template_alias_sfinae
+ {
+
+ struct foo {};
+
+ template<typename T>
+ using member = typename T::member_type;
+
+ template<typename T>
+ void func(...) {}
+
+ template<typename T>
+ void func(member<T>*) {}
+
+ void test();
+
+ void test() { func<foo>(0); }
+
+ }
+
+} // namespace cxx11
+
+#endif // __cplusplus >= 201103L
+
+
+
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+ ax_cv_cxx_compile_cxx11_FOR_BUILD=yes
+else
+ ax_cv_cxx_compile_cxx11_FOR_BUILD=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ax_cv_cxx_compile_cxx11_FOR_BUILD" >&5
+$as_echo "$ax_cv_cxx_compile_cxx11_FOR_BUILD" >&6; }
+ if test x$ax_cv_cxx_compile_cxx11_FOR_BUILD = xyes; then
+ ac_success=yes
+ fi
+
+ if test x$ac_success = xno; then
+ for alternative in ${ax_cxx_compile_alternatives}; do
+ switch="-std=gnu++${alternative}"
+ cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_FOR_BUILD_$switch" | $as_tr_sh`
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5
+$as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; }
+if eval \${$cachevar+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ ac_save_CXX="$CXX"
+ CXX="$CXX $switch"
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+
+// If the compiler admits that it is not ready for C++11, why torture it?
+// Hopefully, this will speed up the test.
+
+#ifndef __cplusplus
+
+#error "This is not a C++ compiler"
+
+#elif __cplusplus < 201103L
+
+#error "This is not a C++11 compiler"
+
+#else
+
+namespace cxx11
+{
+
+ namespace test_static_assert
+ {
+
+ template <typename T>
+ struct check
+ {
+ static_assert(sizeof(int) <= sizeof(T), "not big enough");
+ };
+
+ }
+
+ namespace test_final_override
+ {
+
+ struct Base
+ {
+ virtual ~Base() {}
+ virtual void f() {}
+ };
+
+ struct Derived : public Base
+ {
+ virtual ~Derived() override {}
+ virtual void f() override {}
+ };
+
+ }
+
+ namespace test_double_right_angle_brackets
+ {
+
+ template < typename T >
+ struct check {};
+
+ typedef check<void> single_type;
+ typedef check<check<void>> double_type;
+ typedef check<check<check<void>>> triple_type;
+ typedef check<check<check<check<void>>>> quadruple_type;
+
+ }
+
+ namespace test_decltype
+ {
+
+ int
+ f()
+ {
+ int a = 1;
+ decltype(a) b = 2;
+ return a + b;
+ }
+
+ }
+
+ namespace test_type_deduction
+ {
+
+ template < typename T1, typename T2 >
+ struct is_same
+ {
+ static const bool value = false;
+ };
+
+ template < typename T >
+ struct is_same<T, T>
+ {
+ static const bool value = true;
+ };
+
+ template < typename T1, typename T2 >
+ auto
+ add(T1 a1, T2 a2) -> decltype(a1 + a2)
+ {
+ return a1 + a2;
+ }
+
+ int
+ test(const int c, volatile int v)
+ {
+ static_assert(is_same<int, decltype(0)>::value == true, "");
+ static_assert(is_same<int, decltype(c)>::value == false, "");
+ static_assert(is_same<int, decltype(v)>::value == false, "");
+ auto ac = c;
+ auto av = v;
+ auto sumi = ac + av + 'x';
+ auto sumf = ac + av + 1.0;
+ static_assert(is_same<int, decltype(ac)>::value == true, "");
+ static_assert(is_same<int, decltype(av)>::value == true, "");
+ static_assert(is_same<int, decltype(sumi)>::value == true, "");
+ static_assert(is_same<int, decltype(sumf)>::value == false, "");
+ static_assert(is_same<int, decltype(add(c, v))>::value == true, "");
+ return (sumf > 0.0) ? sumi : add(c, v);
+ }
+
+ }
+
+ namespace test_noexcept
+ {
+
+ int f() { return 0; }
+ int g() noexcept { return 0; }
+
+ static_assert(noexcept(f()) == false, "");
+ static_assert(noexcept(g()) == true, "");
+
+ }
+
+ namespace test_constexpr
+ {
+
+ template < typename CharT >
+ unsigned long constexpr
+ strlen_c_r(const CharT *const s, const unsigned long acc) noexcept
+ {
+ return *s ? strlen_c_r(s + 1, acc + 1) : acc;
+ }
+
+ template < typename CharT >
+ unsigned long constexpr
+ strlen_c(const CharT *const s) noexcept
+ {
+ return strlen_c_r(s, 0UL);
+ }
+
+ static_assert(strlen_c("") == 0UL, "");
+ static_assert(strlen_c("1") == 1UL, "");
+ static_assert(strlen_c("example") == 7UL, "");
+ static_assert(strlen_c("another\0example") == 7UL, "");
+
+ }
+
+ namespace test_rvalue_references
+ {
+
+ template < int N >
+ struct answer
+ {
+ static constexpr int value = N;
+ };
+
+ answer<1> f(int&) { return answer<1>(); }
+ answer<2> f(const int&) { return answer<2>(); }
+ answer<3> f(int&&) { return answer<3>(); }
+
+ void
+ test()
+ {
+ int i = 0;
+ const int c = 0;
+ static_assert(decltype(f(i))::value == 1, "");
+ static_assert(decltype(f(c))::value == 2, "");
+ static_assert(decltype(f(0))::value == 3, "");
+ }
+
+ }
+
+ namespace test_uniform_initialization
+ {
+
+ struct test
+ {
+ static const int zero {};
+ static const int one {1};
+ };
+
+ static_assert(test::zero == 0, "");
+ static_assert(test::one == 1, "");
+
+ }
+
+ namespace test_lambdas
+ {
+
+ void
+ test1()
+ {
+ auto lambda1 = [](){};
+ auto lambda2 = lambda1;
+ lambda1();
+ lambda2();
+ }
+
+ int
+ test2()
+ {
+ auto a = [](int i, int j){ return i + j; }(1, 2);
+ auto b = []() -> int { return '0'; }();
+ auto c = [=](){ return a + b; }();
+ auto d = [&](){ return c; }();
+ auto e = [a, &b](int x) mutable {
+ const auto identity = [](int y){ return y; };
+ for (auto i = 0; i < a; ++i)
+ a += b--;
+ return x + identity(a + b);
+ }(0);
+ return a + b + c + d + e;
+ }
+
+ int
+ test3()
+ {
+ const auto nullary = [](){ return 0; };
+ const auto unary = [](int x){ return x; };
+ using nullary_t = decltype(nullary);
+ using unary_t = decltype(unary);
+ const auto higher1st = [](nullary_t f){ return f(); };
+ const auto higher2nd = [unary](nullary_t f1){
+ return [unary, f1](unary_t f2){ return f2(unary(f1())); };
+ };
+ return higher1st(nullary) + higher2nd(nullary)(unary);
+ }
+
+ }
+
+ namespace test_variadic_templates
+ {
+
+ template <int...>
+ struct sum;
+
+ template <int N0, int... N1toN>
+ struct sum<N0, N1toN...>
+ {
+ static constexpr auto value = N0 + sum<N1toN...>::value;
+ };
+
+ template <>
+ struct sum<>
+ {
+ static constexpr auto value = 0;
+ };
+
+ static_assert(sum<>::value == 0, "");
+ static_assert(sum<1>::value == 1, "");
+ static_assert(sum<23>::value == 23, "");
+ static_assert(sum<1, 2>::value == 3, "");
+ static_assert(sum<5, 5, 11>::value == 21, "");
+ static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, "");
+
+ }
+
+ // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae
+ // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function
+ // because of this.
+ namespace test_template_alias_sfinae
+ {
+
+ struct foo {};
+
+ template<typename T>
+ using member = typename T::member_type;
+
+ template<typename T>
+ void func(...) {}
+
+ template<typename T>
+ void func(member<T>*) {}
+
+ void test();
+
+ void test() { func<foo>(0); }
+
+ }
+
+} // namespace cxx11
+
+#endif // __cplusplus >= 201103L
+
+
+
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+ eval $cachevar=yes
+else
+ eval $cachevar=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ CXX="$ac_save_CXX"
+fi
+eval ac_res=\$$cachevar
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+ if eval test x\$$cachevar = xyes; then
+ CXX="$CXX $switch"
+ if test -n "$CXXCPP" ; then
+ CXXCPP="$CXXCPP $switch"
+ fi
+ ac_success=yes
+ break
+ fi
+ done
+ fi
+
+ if test x$ac_success = xno; then
+ for alternative in ${ax_cxx_compile_alternatives}; do
+ for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do
+ cachevar=`$as_echo "ax_cv_cxx_compile_cxx11_FOR_BUILD_$switch" | $as_tr_sh`
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX supports C++11 features with $switch" >&5
+$as_echo_n "checking whether $CXX supports C++11 features with $switch... " >&6; }
+if eval \${$cachevar+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ ac_save_CXX="$CXX"
+ CXX="$CXX $switch"
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+
+// If the compiler admits that it is not ready for C++11, why torture it?
+// Hopefully, this will speed up the test.
+
+#ifndef __cplusplus
+
+#error "This is not a C++ compiler"
+
+#elif __cplusplus < 201103L
+
+#error "This is not a C++11 compiler"
+
+#else
+
+namespace cxx11
+{
+
+ namespace test_static_assert
+ {
+
+ template <typename T>
+ struct check
+ {
+ static_assert(sizeof(int) <= sizeof(T), "not big enough");
+ };
+
+ }
+
+ namespace test_final_override
+ {
+
+ struct Base
+ {
+ virtual ~Base() {}
+ virtual void f() {}
+ };
+
+ struct Derived : public Base
+ {
+ virtual ~Derived() override {}
+ virtual void f() override {}
+ };
+
+ }
+
+ namespace test_double_right_angle_brackets
+ {
+
+ template < typename T >
+ struct check {};
+
+ typedef check<void> single_type;
+ typedef check<check<void>> double_type;
+ typedef check<check<check<void>>> triple_type;
+ typedef check<check<check<check<void>>>> quadruple_type;
+
+ }
+
+ namespace test_decltype
+ {
+
+ int
+ f()
+ {
+ int a = 1;
+ decltype(a) b = 2;
+ return a + b;
+ }
+
+ }
+
+ namespace test_type_deduction
+ {
+
+ template < typename T1, typename T2 >
+ struct is_same
+ {
+ static const bool value = false;
+ };
+
+ template < typename T >
+ struct is_same<T, T>
+ {
+ static const bool value = true;
+ };
+
+ template < typename T1, typename T2 >
+ auto
+ add(T1 a1, T2 a2) -> decltype(a1 + a2)
+ {
+ return a1 + a2;
+ }
+
+ int
+ test(const int c, volatile int v)
+ {
+ static_assert(is_same<int, decltype(0)>::value == true, "");
+ static_assert(is_same<int, decltype(c)>::value == false, "");
+ static_assert(is_same<int, decltype(v)>::value == false, "");
+ auto ac = c;
+ auto av = v;
+ auto sumi = ac + av + 'x';
+ auto sumf = ac + av + 1.0;
+ static_assert(is_same<int, decltype(ac)>::value == true, "");
+ static_assert(is_same<int, decltype(av)>::value == true, "");
+ static_assert(is_same<int, decltype(sumi)>::value == true, "");
+ static_assert(is_same<int, decltype(sumf)>::value == false, "");
+ static_assert(is_same<int, decltype(add(c, v))>::value == true, "");
+ return (sumf > 0.0) ? sumi : add(c, v);
+ }
+
+ }
+
+ namespace test_noexcept
+ {
+
+ int f() { return 0; }
+ int g() noexcept { return 0; }
+
+ static_assert(noexcept(f()) == false, "");
+ static_assert(noexcept(g()) == true, "");
+
+ }
+
+ namespace test_constexpr
+ {
+
+ template < typename CharT >
+ unsigned long constexpr
+ strlen_c_r(const CharT *const s, const unsigned long acc) noexcept
+ {
+ return *s ? strlen_c_r(s + 1, acc + 1) : acc;
+ }
+
+ template < typename CharT >
+ unsigned long constexpr
+ strlen_c(const CharT *const s) noexcept
+ {
+ return strlen_c_r(s, 0UL);
+ }
+
+ static_assert(strlen_c("") == 0UL, "");
+ static_assert(strlen_c("1") == 1UL, "");
+ static_assert(strlen_c("example") == 7UL, "");
+ static_assert(strlen_c("another\0example") == 7UL, "");
+
+ }
+
+ namespace test_rvalue_references
+ {
+
+ template < int N >
+ struct answer
+ {
+ static constexpr int value = N;
+ };
+
+ answer<1> f(int&) { return answer<1>(); }
+ answer<2> f(const int&) { return answer<2>(); }
+ answer<3> f(int&&) { return answer<3>(); }
+
+ void
+ test()
+ {
+ int i = 0;
+ const int c = 0;
+ static_assert(decltype(f(i))::value == 1, "");
+ static_assert(decltype(f(c))::value == 2, "");
+ static_assert(decltype(f(0))::value == 3, "");
+ }
+
+ }
+
+ namespace test_uniform_initialization
+ {
+
+ struct test
+ {
+ static const int zero {};
+ static const int one {1};
+ };
+
+ static_assert(test::zero == 0, "");
+ static_assert(test::one == 1, "");
+
+ }
+
+ namespace test_lambdas
+ {
+
+ void
+ test1()
+ {
+ auto lambda1 = [](){};
+ auto lambda2 = lambda1;
+ lambda1();
+ lambda2();
+ }
+
+ int
+ test2()
+ {
+ auto a = [](int i, int j){ return i + j; }(1, 2);
+ auto b = []() -> int { return '0'; }();
+ auto c = [=](){ return a + b; }();
+ auto d = [&](){ return c; }();
+ auto e = [a, &b](int x) mutable {
+ const auto identity = [](int y){ return y; };
+ for (auto i = 0; i < a; ++i)
+ a += b--;
+ return x + identity(a + b);
+ }(0);
+ return a + b + c + d + e;
+ }
+
+ int
+ test3()
+ {
+ const auto nullary = [](){ return 0; };
+ const auto unary = [](int x){ return x; };
+ using nullary_t = decltype(nullary);
+ using unary_t = decltype(unary);
+ const auto higher1st = [](nullary_t f){ return f(); };
+ const auto higher2nd = [unary](nullary_t f1){
+ return [unary, f1](unary_t f2){ return f2(unary(f1())); };
+ };
+ return higher1st(nullary) + higher2nd(nullary)(unary);
+ }
+
+ }
+
+ namespace test_variadic_templates
+ {
+
+ template <int...>
+ struct sum;
+
+ template <int N0, int... N1toN>
+ struct sum<N0, N1toN...>
+ {
+ static constexpr auto value = N0 + sum<N1toN...>::value;
+ };
+
+ template <>
+ struct sum<>
+ {
+ static constexpr auto value = 0;
+ };
+
+ static_assert(sum<>::value == 0, "");
+ static_assert(sum<1>::value == 1, "");
+ static_assert(sum<23>::value == 23, "");
+ static_assert(sum<1, 2>::value == 3, "");
+ static_assert(sum<5, 5, 11>::value == 21, "");
+ static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, "");
+
+ }
+
+ // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae
+ // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function
+ // because of this.
+ namespace test_template_alias_sfinae
+ {
+
+ struct foo {};
+
+ template<typename T>
+ using member = typename T::member_type;
+
+ template<typename T>
+ void func(...) {}
+
+ template<typename T>
+ void func(member<T>*) {}
+
+ void test();
+
+ void test() { func<foo>(0); }
+
+ }
+
+} // namespace cxx11
+
+#endif // __cplusplus >= 201103L
+
+
+
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+ eval $cachevar=yes
+else
+ eval $cachevar=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ CXX="$ac_save_CXX"
+fi
+eval ac_res=\$$cachevar
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+$as_echo "$ac_res" >&6; }
+ if eval test x\$$cachevar = xyes; then
+ CXX="$CXX $switch"
+ if test -n "$CXXCPP" ; then
+ CXXCPP="$CXXCPP $switch"
+ fi
+ ac_success=yes
+ break
+ fi
+ done
+ if test x$ac_success = xyes; then
+ break
+ fi
+ done
+ fi
+ CXX_FOR_BUILD="$CXX"
+ CXXFLAGS_FOR_BUILD="$CXXFLAGS"
+ CPPFLAGS_FOR_BUILD="$CPPFLAGS"
+ CXX="$ax_cv_cxx_compile_cxx11_orig_cxx"
+ CXXFLAGS="$ax_cv_cxx_compile_cxx11_orig_cxxflags"
+ CPPFLAGS="$ax_cv_cxx_compile_cxx11_orig_cppflags"
+ ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+ if test x$ax_cxx_compile_cxx11_required = xtrue; then
+ if test x$ac_success = xno; then
+ as_fn_error $? "*** A compiler with support for C++11 language features is required." "$LINENO" 5
+ fi
+ fi
+ if test x$ac_success = xno; then
+ HAVE_CXX11_FOR_BUILD=0
+ { $as_echo "$as_me:${as_lineno-$LINENO}: No compiler with C++11 support was found" >&5
+$as_echo "$as_me: No compiler with C++11 support was found" >&6;}
+ else
+ HAVE_CXX11_FOR_BUILD=1
+
+$as_echo "#define HAVE_CXX11_FOR_BUILD 1" >>confdefs.h
+
+ fi
+
+
+ fi
+fi
+
+# Used for setting $lt_cv_objdir
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for objdir" >&5
+$as_echo_n "checking for objdir... " >&6; }
+if ${lt_cv_objdir+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ rm -f .libs 2>/dev/null
+mkdir .libs 2>/dev/null
+if test -d .libs; then
+ lt_cv_objdir=.libs
+else
+ # MS-DOS does not allow filenames that begin with a dot.
+ lt_cv_objdir=_libs
+fi
+rmdir .libs 2>/dev/null
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $lt_cv_objdir" >&5
+$as_echo "$lt_cv_objdir" >&6; }
+objdir=$lt_cv_objdir
+
+
+
+
+
+cat >>confdefs.h <<_ACEOF
+#define LT_OBJDIR "$lt_cv_objdir/"
+_ACEOF
+
+
+
+# Check for GMP, MPFR and MPC
+gmplibs="-lmpc -lmpfr -lgmp"
+gmpinc=
+have_gmp=no
+
+# Specify a location for mpc
+# check for this first so it ends up on the link line before mpfr.
+
+# Check whether --with-mpc was given.
+if test "${with_mpc+set}" = set; then :
+ withval=$with_mpc;
+fi
+
+
+# Check whether --with-mpc-include was given.
+if test "${with_mpc_include+set}" = set; then :
+ withval=$with_mpc_include;
+fi
+
+
+# Check whether --with-mpc-lib was given.
+if test "${with_mpc_lib+set}" = set; then :
+ withval=$with_mpc_lib;
+fi
+
+
+if test "x$with_mpc" != x; then
+ gmplibs="-L$with_mpc/lib $gmplibs"
+ gmpinc="-I$with_mpc/include $gmpinc"
+fi
+if test "x$with_mpc_include" != x; then
+ gmpinc="-I$with_mpc_include $gmpinc"
+fi
+if test "x$with_mpc_lib" != x; then
+ gmplibs="-L$with_mpc_lib $gmplibs"
+fi
+if test "x$with_mpc$with_mpc_include$with_mpc_lib" = x && test -d ${srcdir}/mpc; then
+ gmplibs='-L$$r/$(HOST_SUBDIR)/mpc/src/'"$lt_cv_objdir $gmplibs"
+ gmpinc='-I$$s/mpc/src '"$gmpinc"
+ # Do not test the mpc version. Assume that it is sufficient, since
+ # it is in the source tree, and the library has not been built yet
+ # but it would be included on the link line in the version check below
+ # hence making the test fail.
+ have_gmp=yes
+fi
+
+# Specify a location for mpfr
+# check for this first so it ends up on the link line before gmp.