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b0de100978
Redefining keywords is undefined behavior and should therefore not be presented as something acceptable. Furthermore the code is now easier to read.
127 lines
3.4 KiB
C++
127 lines
3.4 KiB
C++
///////////////////////////////////////////////////////////////////////////////
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//
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// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
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//
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// This code is licensed under the MIT License (MIT).
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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//
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///////////////////////////////////////////////////////////////////////////////
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#pragma once
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#ifndef GSL_UTIL_H
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#define GSL_UTIL_H
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#include "gsl_assert.h" // GSL_ENSURES/GSL_EXPECTS
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#include <array>
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#include <utility>
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#include <exception>
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#define GSL_IMPL_CONSTEXPR constexpr
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#define GSL_IMPL_NOEXCEPT noexcept
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#ifdef _MSC_VER
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// No MSVC does constexpr fully yet
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#undef GSL_IMPL_CONSTEXPR
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#define GSL_IMPL_CONSTEXPR
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// MSVC 2013 workarounds
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#if _MSC_VER <= 1800
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// noexcept is not understood
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#undef GSL_IMPL_NOEXCEPT
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#define GSL_IMPL_NOEXCEPT
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// turn off some misguided warnings
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#pragma warning(push)
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#pragma warning(disable: 4351) // warns about newly introduced aggregate initializer behavior
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#endif // _MSC_VER <= 1800
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#endif // _MSC_VER
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namespace gsl
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{
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//
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// GSL.util: utilities
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//
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// final_act allows you to ensure something gets run at the end of a scope
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template <class F>
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class final_act
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{
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public:
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explicit final_act(F f) GSL_IMPL_NOEXCEPT
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: f_(std::move(f)), invoke_(true)
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{}
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final_act(final_act&& other) GSL_IMPL_NOEXCEPT
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: f_(std::move(other.f_)), invoke_(other.invoke_)
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{ other.invoke_ = false; }
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final_act(const final_act&) = delete;
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final_act& operator=(const final_act&) = delete;
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~final_act() GSL_IMPL_NOEXCEPT { if (invoke_) f_(); }
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private:
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F f_;
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bool invoke_;
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};
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// finally() - convenience function to generate a final_act
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template <class F>
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inline final_act<F> finally(const F &f)
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GSL_IMPL_NOEXCEPT { return final_act<F>(f); }
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template <class F>
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inline final_act<F> finally(F &&f) GSL_IMPL_NOEXCEPT
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{ return final_act<F>(std::forward<F>(f)); }
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// narrow_cast(): a searchable way to do narrowing casts of values
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template<class T, class U>
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inline GSL_IMPL_CONSTEXPR T narrow_cast(U u) GSL_IMPL_NOEXCEPT
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{ return static_cast<T>(u); }
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struct narrowing_error : public std::exception {};
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// narrow() : a checked version of narrow_cast() that throws if the cast changed the value
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template<class T, class U>
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inline T narrow(U u)
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{ T t = narrow_cast<T>(u); if (static_cast<U>(t) != u) throw narrowing_error(); return t; }
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//
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// at() - Bounds-checked way of accessing static arrays, std::array, std::vector
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//
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template <class T, size_t N>
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GSL_IMPL_CONSTEXPR T& at(T(&arr)[N], size_t index)
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{ GSL_EXPECTS(index < N); return arr[index]; }
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template <class T, size_t N>
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GSL_IMPL_CONSTEXPR T& at(std::array<T, N>& arr, size_t index)
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{ GSL_EXPECTS(index < N); return arr[index]; }
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template <class Cont>
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GSL_IMPL_CONSTEXPR typename Cont::value_type& at(Cont& cont, size_t index)
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{ GSL_EXPECTS(index < cont.size()); return cont[index]; }
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} // namespace gsl
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#undef GSL_IMPL_CONSTEXPR
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#undef GSL_IMPL_NOEXCEPT
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#if defined(_MSC_VER) and (_MSC_VER <= 1800)
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#pragma warning(pop)
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#endif // _MSC_VER <= 1800
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#endif // GSL_UTIL_H
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