git
/
gcc
mirror of git://gcc.gnu.org/git/gcc.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

string_view: Rep empty string with unit-length static constexpr string. 

2013-11-21  Edward Smith-Rowland  <3dw4rd@verizon.net>

	* include/experimental/string_view: Rep empty string with unit-length
	static constexpr string. Uncomment _GLIBCXX_VISIBILITY. Enforce
	invariant of no nullptr string pointer.
	* include/experimental/string_view.tcc: Ditto.
	* testsuite/experimental/string_view/cons/char/1.cc: data() for empty
	string_view is no longer nullptr.
	* testsuite/experimental/string_view/cons/wchar_t/1.cc: Ditto.
	* testsuite/experimental/string_view/operations/data/char/1.cc: Ditto.
	* testsuite/experimental/string_view/operations/data/wchar_t/1.cc:
	Ditto.

From-SVN: r205213
This commit is contained in:
Edward Smith-Rowland 2013-11-21 12:30:37 +00:00 committed by Edward Smith-Rowland
parent d2ae7b11b5
commit 32f9be169c
7 changed files with 52 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
libstdc++-v3/ChangeLog
View File

@ -1,3 +1,16 @@
2013-11-21 Edward Smith-Rowland <3dw4rd@verizon.net>
* include/experimental/string_view: Rep empty string with unit-length
static constexpr string. Uncomment _GLIBCXX_VISIBILITY. Enforce
invariant of no nullptr string pointer.
* include/experimental/string_view.tcc: Ditto.
* testsuite/experimental/string_view/cons/char/1.cc: data() for empty
string_view is no longer nullptr.
* testsuite/experimental/string_view/cons/wchar_t/1.cc: Ditto.
* testsuite/experimental/string_view/operations/data/char/1.cc: Ditto.
* testsuite/experimental/string_view/operations/data/wchar_t/1.cc:
Ditto.
2013-11-21 Edward Smith-Rowland <3dw4rd@verizon.net>
Implement __gnu_cxx::hypergeometric_distribution.

24
libstdc++-v3/include/experimental/string_view
View File

@ -43,7 +43,7 @@
#include <string>
#include <limits>
namespace std //_GLIBCXX_VISIBILITY(default)
namespace std _GLIBCXX_VISIBILITY(default)
{
namespace experimental
{
@ -66,6 +66,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
* _CharT* _M_str
* size_t _M_len
* @endcode
*
* A basic_string_view represents an empty string with a static constexpr
* length one string:
*
* @code
* static constexpr value_type _S_empty_str[1]{0};
* @endcode
*/
template<typename _CharT, typename _Traits = char_traits<_CharT>>
class basic_string_view
@ -92,7 +99,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
constexpr
basic_string_view() noexcept
: _M_len{0}, _M_str{nullptr}
: _M_len{0}, _M_str{_S_empty_str}
{ }
constexpr basic_string_view(const basic_string_view&) noexcept = default;
@ -104,11 +111,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{ }
constexpr basic_string_view(const _CharT* __str)
: _M_len{__str == nullptr ? 0 : traits_type::length(__str)}, _M_str{__str}
: _M_len{__str == nullptr ? 0 : traits_type::length(__str)},
_M_str{__str == nullptr ? _S_empty_str : __str}
{ }
constexpr basic_string_view(const _CharT* __str, size_type __len)
: _M_len{__len}, _M_str{__str}
: _M_len{__str == nullptr ? 0 :__len},
_M_str{__str == nullptr || __len == 0 ? _S_empty_str : __str}
{ }
basic_string_view&
@ -185,7 +194,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
"(which is %zu) >= this->size() "
"(which is %zu)"),
__pos, this->size()),
*static_cast<pointer>(nullptr));
_S_empty_str[0]);
}
constexpr const _CharT&
@ -211,7 +220,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
clear() noexcept
{
this->_M_len = 0;
this->_M_str = nullptr;
this->_M_str = _S_empty_str;
}
void
@ -408,6 +417,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
}
private:
static constexpr const int
_S_compare(size_type __n1, size_type __n2) noexcept
{
@ -418,6 +428,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
: static_cast<int>(difference_type{__n1 - __n2});
}
static constexpr value_type _S_empty_str[1]{};
size_t _M_len;
const _CharT* _M_str;
};

6
libstdc++-v3/include/experimental/string_view.tcc
View File

@ -40,12 +40,16 @@
# include <bits/c++14_warning.h>
#else
namespace std //_GLIBCXX_VISIBILITY(default)
namespace std _GLIBCXX_VISIBILITY(default)
{
namespace experimental
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _CharT, typename _Traits>
constexpr _CharT
basic_string_view<_CharT, _Traits>::_S_empty_str[1];
template<typename _CharT, typename _Traits>
typename basic_string_view<_CharT, _Traits>::size_type
basic_string_view<_CharT, _Traits>::

11
libstdc++-v3/testsuite/experimental/string_view/cons/char/1.cc
View File

@ -33,7 +33,7 @@ test01()
// basic_string_view()
const std::experimental::string_view str00{};
VERIFY( str00.length() == 0 );
VERIFY( str00.data() == nullptr );
VERIFY( str00.data() != nullptr );
// basic_string_view(const char*)
const char str_lit01[] = "rodeo beach, marin";
@ -53,10 +53,11 @@ test01()
std::experimental::string_view str05{str_lit01, len_lit01};
VERIFY( str05.length() == len_lit01 );
VERIFY( str05.data() == str_lit01 );
// This is invalid and unchecked.
//std::experimental::string_view str06{nullptr, len_lit01};
//VERIFY( str06.length() == 0 );
//VERIFY( str06.data() == nullptr );
// basic_string_view(const char* s, std::size_t l)
std::experimental::string_view str06{nullptr, len_lit01};
VERIFY( str06.length() == 0 );
VERIFY( str06.data() != nullptr );
// basic_string_view(basic_string& s)
std::string istr07(10, 'z');

11
libstdc++-v3/testsuite/experimental/string_view/cons/wchar_t/1.cc
View File

@ -33,7 +33,7 @@ test01()
// basic_string_view()
const std::experimental::wstring_view str00{};
VERIFY( str00.length() == 0 );
VERIFY( str00.data() == nullptr );
VERIFY( str00.data() != nullptr );
// basic_string_view(const char*)
const wchar_t str_lit01[] = L"rodeo beach, marin";
@ -53,10 +53,11 @@ test01()
std::experimental::wstring_view str05{str_lit01, len_lit01};
VERIFY( str05.length() == len_lit01 );
VERIFY( str05.data() == str_lit01 );
// This is invalid and unchecked.
//std::experimental::wstring_view str06{nullptr, len_lit01};
//VERIFY( str06.length() == 0 );
//VERIFY( str06.data() == nullptr );
// basic_string_view(const wchar_t* s, std::size_t l)
std::experimental::wstring_view str06{nullptr, len_lit01};
VERIFY( str06.length() == 0 );
VERIFY( str06.data() != nullptr );
// basic_string_view(basic_string& s)
std::wstring istr07(10, L'z');

4
libstdc++-v3/testsuite/experimental/string_view/operations/data/char/1.cc
View File

@ -29,10 +29,10 @@ test01()
std::experimental::string_view empty;
// data() for size == 0 is non-NULL?
// data() for size == 0 is non-NULL.
VERIFY( empty.size() == 0 );
const std::experimental::string_view::value_type* p = empty.data();
VERIFY( p == nullptr );
VERIFY( p );
return 0;
}

4
libstdc++-v3/testsuite/experimental/string_view/operations/data/wchar_t/1.cc
View File

@ -29,10 +29,10 @@ test01()
std::experimental::wstring_view empty;
// data() for size == 0 is non-NULL?
// data() for size == 0 is non-NULL.
VERIFY( empty.size() == 0 );
const std::experimental::wstring_view::value_type* p = empty.data();
VERIFY( p == nullptr );
VERIFY( p );
return 0;
}