diff mbox

constexpr basic_string_view as required by C++17

Message ID CAHYwrxdNdDgWSoUS_Yyuk=+yw+tHDXWWpo13nARgouXQAPF13Q@mail.gmail.com
State New
Headers show

Commit Message

Benjamin Buch Aug. 18, 2017, 2:49 p.m. UTC 
The current implementation does miss a lot of constexpr in
basic_string_view. (Bug 70483)

The patch adds the missing constexpr's as required by C++17. I did run
the the stdlibc++-v3 testsuite and got no errors. I didn't changes the
basic_string_view test cases, because I couldn't find a pattern in it
how to test if the function declarations are constexpr. (This is my
first patch for GCC.)
diff mbox

Patch

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index fd9a6afb..86f1a72 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@ 
+2017-08-18  Benjamin Buch  <benni.buch@gmail.com>
+
+	* include/std/string_view: Added constexpr as required by the C++17.
+	* include/bits/string_view.tcc: Likewise.
+
 2017-08-11  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/81808
@@ -2783,7 +2788,7 @@ 
 2017-01-01  Jakub Jelinek  <jakub@redhat.com>
 
 	Update copyright years.
-
+
 Copyright (C) 2017 Free Software Foundation, Inc.
 
 Copying and distribution of this file, with or without modification,
diff --git a/libstdc++-v3/include/bits/string_view.tcc b/libstdc++-v3/include/bits/string_view.tcc
index f4bd50f..b8ab78c 100644
--- a/libstdc++-v3/include/bits/string_view.tcc
+++ b/libstdc++-v3/include/bits/string_view.tcc
@@ -45,7 +45,7 @@  namespace std _GLIBCXX_VISIBILITY(default)
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   template<typename _CharT, typename _Traits>
-    typename basic_string_view<_CharT, _Traits>::size_type
+    constexpr typename basic_string_view<_CharT, _Traits>::size_type
     basic_string_view<_CharT, _Traits>::
     find(const _CharT* __str, size_type __pos, size_type __n) const noexcept
     {
@@ -66,7 +66,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   template<typename _CharT, typename _Traits>
-    typename basic_string_view<_CharT, _Traits>::size_type
+    constexpr typename basic_string_view<_CharT, _Traits>::size_type
     basic_string_view<_CharT, _Traits>::
     find(_CharT __c, size_type __pos) const noexcept
     {
@@ -82,7 +82,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   template<typename _CharT, typename _Traits>
-    typename basic_string_view<_CharT, _Traits>::size_type
+    constexpr typename basic_string_view<_CharT, _Traits>::size_type
     basic_string_view<_CharT, _Traits>::
     rfind(const _CharT* __str, size_type __pos, size_type __n) const noexcept
     {
@@ -102,7 +102,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   template<typename _CharT, typename _Traits>
-    typename basic_string_view<_CharT, _Traits>::size_type
+    constexpr typename basic_string_view<_CharT, _Traits>::size_type
     basic_string_view<_CharT, _Traits>::
     rfind(_CharT __c, size_type __pos) const noexcept
     {
@@ -119,7 +119,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   template<typename _CharT, typename _Traits>
-    typename basic_string_view<_CharT, _Traits>::size_type
+    constexpr typename basic_string_view<_CharT, _Traits>::size_type
     basic_string_view<_CharT, _Traits>::
     find_first_of(const _CharT* __str, size_type __pos, size_type __n) const
     {
@@ -135,7 +135,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   template<typename _CharT, typename _Traits>
-    typename basic_string_view<_CharT, _Traits>::size_type
+    constexpr typename basic_string_view<_CharT, _Traits>::size_type
     basic_string_view<_CharT, _Traits>::
     find_last_of(const _CharT* __str, size_type __pos, size_type __n) const
     {
@@ -156,7 +156,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   template<typename _CharT, typename _Traits>
-    typename basic_string_view<_CharT, _Traits>::size_type
+    constexpr typename basic_string_view<_CharT, _Traits>::size_type
     basic_string_view<_CharT, _Traits>::
     find_first_not_of(const _CharT* __str, size_type __pos, size_type __n) const
     {
@@ -168,7 +168,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   template<typename _CharT, typename _Traits>
-    typename basic_string_view<_CharT, _Traits>::size_type
+    constexpr typename basic_string_view<_CharT, _Traits>::size_type
     basic_string_view<_CharT, _Traits>::
     find_first_not_of(_CharT __c, size_type __pos) const noexcept
     {
@@ -179,7 +179,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   template<typename _CharT, typename _Traits>
-    typename basic_string_view<_CharT, _Traits>::size_type
+    constexpr typename basic_string_view<_CharT, _Traits>::size_type
     basic_string_view<_CharT, _Traits>::
     find_last_not_of(const _CharT* __str, size_type __pos, size_type __n) const
     {
@@ -200,7 +200,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   template<typename _CharT, typename _Traits>
-    typename basic_string_view<_CharT, _Traits>::size_type
+    constexpr typename basic_string_view<_CharT, _Traits>::size_type
     basic_string_view<_CharT, _Traits>::
     find_last_not_of(_CharT __c, size_type __pos) const noexcept
     {
diff --git a/libstdc++-v3/include/std/string_view b/libstdc++-v3/include/std/string_view
index 88a7686..8b4ac05 100644
--- a/libstdc++-v3/include/std/string_view
+++ b/libstdc++-v3/include/std/string_view
@@ -106,7 +106,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
         _M_str{__str}
       { }
 
-      basic_string_view&
+      constexpr basic_string_view&
       operator=(const basic_string_view&) noexcept = default;
 
       // [string.view.iterators], iterators
@@ -127,19 +127,19 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
       cend() const noexcept
       { return this->_M_str + this->_M_len; }
 
-      const_reverse_iterator
+      constexpr const_reverse_iterator
       rbegin() const noexcept
       { return const_reverse_iterator(this->end()); }
 
-      const_reverse_iterator
+      constexpr const_reverse_iterator
       rend() const noexcept
       { return const_reverse_iterator(this->begin()); }
 
-      const_reverse_iterator
+      constexpr const_reverse_iterator
       crbegin() const noexcept
       { return const_reverse_iterator(this->end()); }
 
-      const_reverse_iterator
+      constexpr const_reverse_iterator
       crend() const noexcept
       { return const_reverse_iterator(this->begin()); }
 
@@ -208,7 +208,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       // [string.view.modifiers], modifiers:
 
-      void
+      constexpr void
       remove_prefix(size_type __n)
       {
 	__glibcxx_assert(this->_M_len >= __n);
@@ -216,11 +216,11 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	this->_M_len -= __n;
       }
 
-      void
+      constexpr void
       remove_suffix(size_type __n)
       { this->_M_len -= __n; }
 
-      void
+      constexpr void
       swap(basic_string_view& __sv) noexcept
       {
 	std::swap(this->_M_len, __sv._M_len);
@@ -261,7 +261,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
 				     __pos, this->size()), basic_string_view{});
       }
 
-      int
+      constexpr int
       compare(basic_string_view __str) const noexcept
       {
 	int __ret = traits_type::compare(this->_M_str, __str._M_str,
@@ -271,24 +271,24 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	return __ret;
       }
 
-      int
+      constexpr int
       compare(size_type __pos1, size_type __n1, basic_string_view __str) const
       { return this->substr(__pos1, __n1).compare(__str); }
 
-      int
+      constexpr int
       compare(size_type __pos1, size_type __n1,
 	      basic_string_view __str, size_type __pos2, size_type __n2) const
       { return this->substr(__pos1, __n1).compare(__str.substr(__pos2, __n2)); }
 
-      int
+      constexpr int
       compare(const _CharT* __str) const noexcept
       { return this->compare(basic_string_view{__str}); }
 
-      int
+      constexpr int
       compare(size_type __pos1, size_type __n1, const _CharT* __str) const
       { return this->substr(__pos1, __n1).compare(basic_string_view{__str}); }
 
-      int
+      constexpr int
       compare(size_type __pos1, size_type __n1,
 	      const _CharT* __str, size_type __n2) const
       {
@@ -296,97 +296,97 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
 		   .compare(basic_string_view(__str, __n2));
       }
 
-      size_type
+      constexpr size_type
       find(basic_string_view __str, size_type __pos = 0) const noexcept
       { return this->find(__str._M_str, __pos, __str._M_len); }
 
-      size_type
+      constexpr size_type
       find(_CharT __c, size_type __pos=0) const noexcept;
 
-      size_type
+      constexpr size_type
       find(const _CharT* __str, size_type __pos, size_type __n) const noexcept;
 
-      size_type
+      constexpr size_type
       find(const _CharT* __str, size_type __pos=0) const noexcept
       { return this->find(__str, __pos, traits_type::length(__str)); }
 
-      size_type
+      constexpr size_type
       rfind(basic_string_view __str, size_type __pos = npos) const noexcept
       { return this->rfind(__str._M_str, __pos, __str._M_len); }
 
-      size_type
+      constexpr size_type
       rfind(_CharT __c, size_type __pos = npos) const noexcept;
 
-      size_type
+      constexpr size_type
       rfind(const _CharT* __str, size_type __pos, size_type __n) const noexcept;
 
-      size_type
+      constexpr size_type
       rfind(const _CharT* __str, size_type __pos = npos) const noexcept
       { return this->rfind(__str, __pos, traits_type::length(__str)); }
 
-      size_type
+      constexpr size_type
       find_first_of(basic_string_view __str, size_type __pos = 0) const noexcept
       { return this->find_first_of(__str._M_str, __pos, __str._M_len); }
 
-      size_type
+      constexpr size_type
       find_first_of(_CharT __c, size_type __pos = 0) const noexcept
       { return this->find(__c, __pos); }
 
-      size_type
+      constexpr size_type
       find_first_of(const _CharT* __str, size_type __pos, size_type __n) const;
 
-      size_type
+      constexpr size_type
       find_first_of(const _CharT* __str, size_type __pos = 0) const noexcept
       { return this->find_first_of(__str, __pos, traits_type::length(__str)); }
 
-      size_type
+      constexpr size_type
       find_last_of(basic_string_view __str,
 		   size_type __pos = npos) const noexcept
       { return this->find_last_of(__str._M_str, __pos, __str._M_len); }
 
-      size_type
+      constexpr size_type
       find_last_of(_CharT __c, size_type __pos=npos) const noexcept
       { return this->rfind(__c, __pos); }
 
-      size_type
+      constexpr size_type
       find_last_of(const _CharT* __str, size_type __pos, size_type __n) const;
 
-      size_type
+      constexpr size_type
       find_last_of(const _CharT* __str, size_type __pos = npos) const noexcept
       { return this->find_last_of(__str, __pos, traits_type::length(__str)); }
 
-      size_type
+      constexpr size_type
       find_first_not_of(basic_string_view __str,
 			size_type __pos = 0) const noexcept
       { return this->find_first_not_of(__str._M_str, __pos, __str._M_len); }
 
-      size_type
+      constexpr size_type
       find_first_not_of(_CharT __c, size_type __pos = 0) const noexcept;
 
-      size_type
+      constexpr size_type
       find_first_not_of(const _CharT* __str,
 			size_type __pos, size_type __n) const;
 
-      size_type
+      constexpr size_type
       find_first_not_of(const _CharT* __str, size_type __pos = 0) const noexcept
       {
 	return this->find_first_not_of(__str, __pos,
 				       traits_type::length(__str));
       }
 
-      size_type
+      constexpr size_type
       find_last_not_of(basic_string_view __str,
 		       size_type __pos = npos) const noexcept
       { return this->find_last_not_of(__str._M_str, __pos, __str._M_len); }
 
-      size_type
+      constexpr size_type
       find_last_not_of(_CharT __c, size_type __pos = npos) const noexcept;
 
-      size_type
+      constexpr size_type
       find_last_not_of(const _CharT* __str,
 		       size_type __pos, size_type __n) const;
 
-      size_type
+      constexpr size_type
       find_last_not_of(const _CharT* __str,
 		       size_type __pos = npos) const noexcept
       {
@@ -411,7 +411,7 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	const bool __testoff =  __off < this->size() - __pos;
 	return __testoff ? __off : this->size() - __pos;
       }
-      
+
     private:
 
       static constexpr int
@@ -440,109 +440,109 @@  _GLIBCXX_BEGIN_NAMESPACE_VERSION
   }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator==(basic_string_view<_CharT, _Traits> __x,
                basic_string_view<_CharT, _Traits> __y) noexcept
     { return __x.size() == __y.size() && __x.compare(__y) == 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator==(basic_string_view<_CharT, _Traits> __x,
                __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
     { return __x.size() == __y.size() && __x.compare(__y) == 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator==(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
                basic_string_view<_CharT, _Traits> __y) noexcept
     { return __x.size() == __y.size() && __x.compare(__y) == 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator!=(basic_string_view<_CharT, _Traits> __x,
                basic_string_view<_CharT, _Traits> __y) noexcept
     { return !(__x == __y); }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator!=(basic_string_view<_CharT, _Traits> __x,
                __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
     { return !(__x == __y); }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator!=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
                basic_string_view<_CharT, _Traits> __y) noexcept
     { return !(__x == __y); }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator< (basic_string_view<_CharT, _Traits> __x,
                basic_string_view<_CharT, _Traits> __y) noexcept
     { return __x.compare(__y) < 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator< (basic_string_view<_CharT, _Traits> __x,
                __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
     { return __x.compare(__y) < 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator< (__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
                basic_string_view<_CharT, _Traits> __y) noexcept
     { return __x.compare(__y) < 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator> (basic_string_view<_CharT, _Traits> __x,
                basic_string_view<_CharT, _Traits> __y) noexcept
     { return __x.compare(__y) > 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator> (basic_string_view<_CharT, _Traits> __x,
                __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
     { return __x.compare(__y) > 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator> (__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
                basic_string_view<_CharT, _Traits> __y) noexcept
     { return __x.compare(__y) > 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator<=(basic_string_view<_CharT, _Traits> __x,
                basic_string_view<_CharT, _Traits> __y) noexcept
     { return __x.compare(__y) <= 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator<=(basic_string_view<_CharT, _Traits> __x,
                __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
     { return __x.compare(__y) <= 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator<=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
                basic_string_view<_CharT, _Traits> __y) noexcept
     { return __x.compare(__y) <= 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator>=(basic_string_view<_CharT, _Traits> __x,
                basic_string_view<_CharT, _Traits> __y) noexcept
     { return __x.compare(__y) >= 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator>=(basic_string_view<_CharT, _Traits> __x,
                __detail::__idt<basic_string_view<_CharT, _Traits>> __y) noexcept
     { return __x.compare(__y) >= 0; }
 
   template<typename _CharT, typename _Traits>
-    inline bool
+    constexpr bool
     operator>=(__detail::__idt<basic_string_view<_CharT, _Traits>> __x,
                basic_string_view<_CharT, _Traits> __y) noexcept
     { return __x.compare(__y) >= 0; }