Implement P0426: Constexpr for std::char_traits
llvm-svn: 291741
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 05d57faa2e54a8faf4fd31d0659c8ff24a6fd3da
diff --git a/include/__string b/include/__string
index 0b851b9..8152660 100644
--- a/include/__string
+++ b/include/__string
@@ -26,13 +26,14 @@
typedef streampos pos_type;
typedef mbstate_t state_type;
- static void assign(char_type& c1, const char_type& c2) noexcept;
+ static constexpr void assign(char_type& c1, const char_type& c2) noexcept;
static constexpr bool eq(char_type c1, char_type c2) noexcept;
static constexpr bool lt(char_type c1, char_type c2) noexcept;
- static int compare(const char_type* s1, const char_type* s2, size_t n);
- static size_t length(const char_type* s);
- static const char_type* find(const char_type* s, size_t n, const char_type& a);
+ static constexpr int compare(const char_type* s1, const char_type* s2, size_t n);
+ static constexpr size_t length(const char_type* s);
+ static constexpr const char_type*
+ find(const char_type* s, size_t n, const char_type& a);
static char_type* move(char_type* s1, const char_type* s2, size_t n);
static char_type* copy(char_type* s1, const char_type* s2, size_t n);
static char_type* assign(char_type* s, size_t n, char_type a);
@@ -77,18 +78,19 @@
typedef streampos pos_type;
typedef mbstate_t state_type;
- static inline void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT
- {__c1 = __c2;}
+ static inline void _LIBCPP_CONSTEXPR_AFTER_CXX14
+ assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
{return __c1 == __c2;}
static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
{return __c1 < __c2;}
- static int compare(const char_type* __s1, const char_type* __s2, size_t __n);
- _LIBCPP_INLINE_VISIBILITY
- static size_t length(const char_type* __s);
- _LIBCPP_INLINE_VISIBILITY
- static const char_type* find(const char_type* __s, size_t __n, const char_type& __a);
+ static _LIBCPP_CONSTEXPR_AFTER_CXX14
+ int compare(const char_type* __s1, const char_type* __s2, size_t __n);
+ _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+ size_t length(const char_type* __s);
+ _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+ const char_type* find(const char_type* __s, size_t __n, const char_type& __a);
static char_type* move(char_type* __s1, const char_type* __s2, size_t __n);
_LIBCPP_INLINE_VISIBILITY
static char_type* copy(char_type* __s1, const char_type* __s2, size_t __n);
@@ -108,7 +110,7 @@
};
template <class _CharT>
-int
+_LIBCPP_CONSTEXPR_AFTER_CXX14 int
char_traits<_CharT>::compare(const char_type* __s1, const char_type* __s2, size_t __n)
{
for (; __n; --__n, ++__s1, ++__s2)
@@ -123,7 +125,7 @@
template <class _CharT>
inline
-size_t
+_LIBCPP_CONSTEXPR_AFTER_CXX14 size_t
char_traits<_CharT>::length(const char_type* __s)
{
size_t __len = 0;
@@ -134,7 +136,7 @@
template <class _CharT>
inline
-const _CharT*
+_LIBCPP_CONSTEXPR_AFTER_CXX14 const _CharT*
char_traits<_CharT>::find(const char_type* __s, size_t __n, const char_type& __a)
{
for (; __n; --__n)
@@ -200,18 +202,20 @@
typedef streampos pos_type;
typedef mbstate_t state_type;
- static inline void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT
- {__c1 = __c2;}
+ static inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+ void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
{return __c1 == __c2;}
static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
{return (unsigned char)__c1 < (unsigned char)__c2;}
- static inline int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
- {return __n == 0 ? 0 : memcmp(__s1, __s2, __n);}
- static inline size_t length(const char_type* __s) _NOEXCEPT {return strlen(__s);}
- static inline const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
- {return __n == 0 ? NULL : (const char_type*) memchr(__s, to_int_type(__a), __n);}
+ static inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+ int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
+ {return __n == 0 ? 0 : __builtin_memcmp(__s1, __s2, __n);}
+ static inline size_t _LIBCPP_CONSTEXPR_AFTER_CXX14
+ length(const char_type* __s) _NOEXCEPT {return __builtin_strlen(__s);}
+ static _LIBCPP_CONSTEXPR_AFTER_CXX14
+ const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
static inline char_type* move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
{return __n == 0 ? __s1 : (char_type*) memmove(__s1, __s2, __n);}
static inline char_type* copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
@@ -234,6 +238,26 @@
{return int_type(EOF);}
};
+inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+const char*
+char_traits<char>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
+{
+ if (__n == 0)
+ return NULL;
+#if _LIBCPP_STD_VER <= 14
+ return (const char_type*) memchr(__s, to_int_type(__a), __n);
+#else
+ for (; __n; --__n)
+ {
+ if (eq(*__s, __a))
+ return __s;
+ ++__s;
+ }
+ return NULL;
+#endif
+}
+
+
// char_traits<wchar_t>
template <>
@@ -245,19 +269,19 @@
typedef streampos pos_type;
typedef mbstate_t state_type;
- static inline void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT
- {__c1 = __c2;}
+ static inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+ void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
{return __c1 == __c2;}
static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
{return __c1 < __c2;}
- static inline int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
- {return __n == 0 ? 0 : wmemcmp(__s1, __s2, __n);}
- static inline size_t length(const char_type* __s) _NOEXCEPT
- {return wcslen(__s);}
- static inline const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
- {return __n == 0 ? NULL : (const char_type*)wmemchr(__s, __a, __n);}
+ static _LIBCPP_CONSTEXPR_AFTER_CXX14
+ int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
+ static _LIBCPP_CONSTEXPR_AFTER_CXX14
+ size_t length(const char_type* __s) _NOEXCEPT;
+ static _LIBCPP_CONSTEXPR_AFTER_CXX14
+ const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
static inline char_type* move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
{return __n == 0 ? __s1 : (char_type*)wmemmove(__s1, __s2, __n);}
static inline char_type* copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
@@ -280,6 +304,66 @@
{return int_type(WEOF);}
};
+inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+int
+char_traits<wchar_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
+{
+ if (__n == 0)
+ return 0;
+#if __has_builtin(__builtin_wmemcmp)
+ return __builtin_wmemcmp(__s1, __s2, __n);
+#elif _LIBCPP_STD_VER <= 14
+ return wmemcmp(__s1, __s2, __n);
+#else
+ for (; __n; --__n, ++__s1, ++__s2)
+ {
+ if (lt(*__s1, *__s2))
+ return -1;
+ if (lt(*__s2, *__s1))
+ return 1;
+ }
+ return 0;
+#endif
+}
+
+inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+size_t
+char_traits<wchar_t>::length(const char_type* __s) _NOEXCEPT
+{
+#if __has_builtin(__builtin_wcslen)
+ return __builtin_wcslen(__s);
+#elif _LIBCPP_STD_VER <= 14
+ return wcslen(__s);
+#else
+ size_t __len = 0;
+ for (; !eq(*__s, char_type(0)); ++__s)
+ ++__len;
+ return __len;
+#endif
+}
+
+inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+const wchar_t*
+char_traits<wchar_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
+{
+ if (__n == 0)
+ return NULL;
+#if __has_builtin(__builtin_wmemchr)
+ return __builtin_wmemchr(__s, __a, __n);
+#elif _LIBCPP_STD_VER <= 14
+ return wmemchr(__s, __a, __n);
+#else
+ for (; __n; --__n)
+ {
+ if (eq(*__s, __a))
+ return __s;
+ ++__s;
+ }
+ return NULL;
+#endif
+}
+
+
#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
template <>
@@ -291,19 +375,19 @@
typedef u16streampos pos_type;
typedef mbstate_t state_type;
- static inline void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT
- {__c1 = __c2;}
+ static inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+ void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
{return __c1 == __c2;}
static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
{return __c1 < __c2;}
- _LIBCPP_INLINE_VISIBILITY
- static int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
- _LIBCPP_INLINE_VISIBILITY
- static size_t length(const char_type* __s) _NOEXCEPT;
- _LIBCPP_INLINE_VISIBILITY
- static const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
+ _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+ int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
+ _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+ size_t length(const char_type* __s) _NOEXCEPT;
+ _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+ const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
_LIBCPP_INLINE_VISIBILITY
static char_type* move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
_LIBCPP_INLINE_VISIBILITY
@@ -323,7 +407,7 @@
{return int_type(0xFFFF);}
};
-inline
+inline _LIBCPP_CONSTEXPR_AFTER_CXX14
int
char_traits<char16_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
{
@@ -337,7 +421,7 @@
return 0;
}
-inline
+inline _LIBCPP_CONSTEXPR_AFTER_CXX14
size_t
char_traits<char16_t>::length(const char_type* __s) _NOEXCEPT
{
@@ -347,7 +431,7 @@
return __len;
}
-inline
+inline _LIBCPP_CONSTEXPR_AFTER_CXX14
const char16_t*
char_traits<char16_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
{
@@ -410,19 +494,19 @@
typedef u32streampos pos_type;
typedef mbstate_t state_type;
- static inline void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT
- {__c1 = __c2;}
+ static inline _LIBCPP_CONSTEXPR_AFTER_CXX14
+ void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
{return __c1 == __c2;}
static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
{return __c1 < __c2;}
- _LIBCPP_INLINE_VISIBILITY
- static int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
- _LIBCPP_INLINE_VISIBILITY
- static size_t length(const char_type* __s) _NOEXCEPT;
- _LIBCPP_INLINE_VISIBILITY
- static const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
+ _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+ int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
+ _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+ size_t length(const char_type* __s) _NOEXCEPT;
+ _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
+ const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
_LIBCPP_INLINE_VISIBILITY
static char_type* move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
_LIBCPP_INLINE_VISIBILITY
@@ -442,7 +526,7 @@
{return int_type(0xFFFFFFFF);}
};
-inline
+inline _LIBCPP_CONSTEXPR_AFTER_CXX14
int
char_traits<char32_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
{
@@ -456,7 +540,7 @@
return 0;
}
-inline
+inline _LIBCPP_CONSTEXPR_AFTER_CXX14
size_t
char_traits<char32_t>::length(const char_type* __s) _NOEXCEPT
{
@@ -466,7 +550,7 @@
return __len;
}
-inline
+inline _LIBCPP_CONSTEXPR_AFTER_CXX14
const char32_t*
char_traits<char32_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
{