Move the test for zero-length into the char_traits (from string_view). Add tests to char_traits specializations
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@228981 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/string b/include/string
index fe42bbf..9f4007a 100644
--- a/include/string
+++ b/include/string
@@ -636,7 +636,7 @@
{return (unsigned char)__c1 < (unsigned char)__c2;}
static inline int compare(const char_type* __s1, const char_type* __s2, size_t __n)
- {return memcmp(__s1, __s2, __n);}
+ {return __n == 0 ? 0 : memcmp(__s1, __s2, __n);}
static inline size_t length(const char_type* __s) {return strlen(__s);}
static inline const char_type* find(const char_type* __s, size_t __n, const char_type& __a)
{return (const char_type*)memchr(__s, to_int_type(__a), __n);}
@@ -681,7 +681,7 @@
{return __c1 < __c2;}
static inline int compare(const char_type* __s1, const char_type* __s2, size_t __n)
- {return wmemcmp(__s1, __s2, __n);}
+ {return __n == 0 ? 0 : wmemcmp(__s1, __s2, __n);}
static inline size_t length(const char_type* __s)
{return wcslen(__s);}
static inline const char_type* find(const char_type* __s, size_t __n, const char_type& __a)