From: Jonathan Wakely <jwakely@redhat.com>
Date: Fri, 1 Dec 2017 16:10:31 +0000 (+0000)
Subject: Fix narrowing conversions in string_view types
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=ad8fda29e6274dd28aa11d15e98cc777f56ffb37;p=gcc.git

Fix narrowing conversions in string_view types

	* include/experimental/string_view (basic_string_view::_S_compare):
	Use value-init so narrowing conversions are not ill-formed.
	* include/std/string_view (basic_string_view::_S_compare): Likewise.

From-SVN: r255321
---

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 14b65e3575e..601bc8a065d 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,9 @@
 2017-12-01  Jonathan Wakely  <jwakely@redhat.com>
 
+	* include/experimental/string_view (basic_string_view::_S_compare):
+	Use value-init so narrowing conversions are not ill-formed.
+	* include/std/string_view (basic_string_view::_S_compare): Likewise.
+
 	* include/bits/basic_string.h (operator""s): Add pragmas to disable
 	-Wliteral-suffix warnings.
 	* include/experimental/string_view (operator""sv): Likewise.
diff --git a/libstdc++-v3/include/experimental/string_view b/libstdc++-v3/include/experimental/string_view
index 96d1f58f8e9..ef171ecc025 100644
--- a/libstdc++-v3/include/experimental/string_view
+++ b/libstdc++-v3/include/experimental/string_view
@@ -422,11 +422,11 @@ inline namespace fundamentals_v1
       static constexpr int
       _S_compare(size_type __n1, size_type __n2) noexcept
       {
-	return difference_type{__n1 - __n2} > std::numeric_limits<int>::max()
+	return difference_type(__n1 - __n2) > std::numeric_limits<int>::max()
 	     ? std::numeric_limits<int>::max()
-	     : difference_type{__n1 - __n2} < std::numeric_limits<int>::min()
+	     : difference_type(__n1 - __n2) < std::numeric_limits<int>::min()
 	     ? std::numeric_limits<int>::min()
-	     : static_cast<int>(difference_type{__n1 - __n2});
+	     : static_cast<int>(difference_type(__n1 - __n2));
       }
 
       size_t	    _M_len;
diff --git a/libstdc++-v3/include/std/string_view b/libstdc++-v3/include/std/string_view
index 1266a07d04f..3b2901ab3c6 100644
--- a/libstdc++-v3/include/std/string_view
+++ b/libstdc++-v3/include/std/string_view
@@ -408,7 +408,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       static constexpr int
       _S_compare(size_type __n1, size_type __n2) noexcept
       {
-	const difference_type __diff{__n1 - __n2};
+	const difference_type __diff = __n1 - __n2;
 	if (__diff > std::numeric_limits<int>::max())
 	  return std::numeric_limits<int>::max();
 	if (__diff < std::numeric_limits<int>::min())