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1///////////////////////////////////////////////////////////////////////////////
2//
3// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
4//
5// This code is licensed under the MIT License (MIT).
6//
7// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
8// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
9// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
10// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
11// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
12// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
13// THE SOFTWARE.
14//
15///////////////////////////////////////////////////////////////////////////////
16
17#ifndef GSL_ALGORITHM_H
18#define GSL_ALGORITHM_H
19
20#include <gsl/gsl_assert> // for Expects
21#include <gsl/span>       // for dynamic_extent, span
22
23#include <algorithm>   // for copy_n
24#include <cstddef>     // for ptrdiff_t
25#include <type_traits> // for is_assignable
26
27#ifdef _MSC_VER
28#pragma warning(push)
29
30// turn off some warnings that are noisy about our Expects statements
31#pragma warning(disable : 4127) // conditional expression is constant
32#pragma warning(disable : 4996) // unsafe use of std::copy_n
33
34#endif // _MSC_VER
35
36namespace gsl
37{
38// Note: this will generate faster code than std::copy using span iterator in older msvc+stl
39// not necessary for msvc since VS2017 15.8 (_MSC_VER >= 1915)
40template <class SrcElementType, std::ptrdiff_t SrcExtent, class DestElementType,
41          std::ptrdiff_t DestExtent>
42void copy(span<SrcElementType, SrcExtent> src, span<DestElementType, DestExtent> dest)
43{
44    static_assert(std::is_assignable<decltype(*dest.data()), decltype(*src.data())>::value,
45                  "Elements of source span can not be assigned to elements of destination span");
46    static_assert(SrcExtent == dynamic_extent || DestExtent == dynamic_extent ||
47                      (SrcExtent <= DestExtent),
48                  "Source range is longer than target range");
49
50    Expects(dest.size() >= src.size());
51    GSL_SUPPRESS(stl.1) // NO-FORMAT: attribute
52    std::copy_n(src.data(), src.size(), dest.data());
53}
54
55} // namespace gsl
56
57#ifdef _MSC_VER
58#pragma warning(pop)
59#endif // _MSC_VER
60
61#endif // GSL_ALGORITHM_H
62