xref: /llvm-project-15.0.7/libcxx/test/std/strings/string.view/string.view.capacity/capacity.pass.cpp (revision 3cd4531b)

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// UNSUPPORTED: !stdlib=libc++ && (c++03 || c++11 || c++14)

// <string_view>

// [string.view.capacity], capacity
// constexpr size_type size()     const noexcept;
// constexpr size_type length()   const noexcept;
// constexpr size_type max_size() const noexcept;
// constexpr bool empty()         const noexcept;

#include <string_view>
#include <cassert>
#include <iterator>
#include <limits>

#include "test_macros.h"

template<typename SV>
void test1 () {
#if TEST_STD_VER > 11
    {
    constexpr SV sv1;
    static_assert ( sv1.size() == 0, "" );
    static_assert ( sv1.empty(), "");
    static_assert ( sv1.size() == sv1.length(), "" );
    static_assert ( sv1.max_size() > sv1.size(), "");
    }
#endif

    {
    SV sv1;
    ASSERT_NOEXCEPT(sv1.size());
    ASSERT_NOEXCEPT(sv1.empty());
    ASSERT_NOEXCEPT(sv1.max_size());
    ASSERT_NOEXCEPT(sv1.length());
    assert ( sv1.size() == 0 );
    assert ( sv1.empty());
    assert ( sv1.size() == sv1.length());
    assert ( sv1.max_size() > sv1.size());
    }

    // Sanity check max_size() -- a string_view can't store more bytes than a single object
    // can contain. Any implementation that fails this check is certainly lying.
    {
        typedef typename SV::value_type CharT;
        typedef typename SV::size_type Size;
        SV sv;
        assert(sv.max_size() <= std::numeric_limits<Size>::max() / sizeof(CharT));
        LIBCPP_ASSERT(sv.max_size() == std::numeric_limits<Size>::max() / sizeof(CharT));
    }
}

template<typename CharT>
void test2 ( const CharT *s, size_t len ) {
    {
    std::basic_string_view<CharT> sv1 ( s );
    assert ( sv1.size() == len );
    assert ( sv1.data() == s );
    assert ( sv1.empty() == (len == 0));
    assert ( sv1.size() == sv1.length());
    assert ( sv1.max_size() > sv1.size());
#if TEST_STD_VER > 14
//  make sure we pick up std::size, too!
    assert ( sv1.size() == std::size(sv1));
    assert ( sv1.empty() == std::empty(sv1));
#endif
    }
}

int main(int, char**) {
    test1<std::string_view> ();
#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
    test1<std::u8string_view> ();
#endif
    test1<std::u16string_view> ();
    test1<std::u32string_view> ();
#ifndef TEST_HAS_NO_WIDE_CHARACTERS
    test1<std::wstring_view> ();
#endif

    test2 ( "ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE", 105 );
    test2 ( "ABCDE", 5 );
    test2 ( "a", 1 );
    test2 ( "", 0 );

#ifndef TEST_HAS_NO_WIDE_CHARACTERS
    test2 ( L"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE", 105 );
    test2 ( L"ABCDE", 5 );
    test2 ( L"a", 1 );
    test2 ( L"", 0 );
#endif

#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
    test2 ( u8"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE", 105 );
    test2 ( u8"ABCDE", 5 );
    test2 ( u8"a", 1 );
    test2 ( u8"", 0 );
#endif

#if TEST_STD_VER >= 11
    test2 ( u"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE", 105 );
    test2 ( u"ABCDE", 5 );
    test2 ( u"a", 1 );
    test2 ( u"", 0 );

    test2 ( U"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE", 105 );
    test2 ( U"ABCDE", 5 );
    test2 ( U"a", 1 );
    test2 ( U"", 0 );
#endif

  return 0;
}