ceph/src/jaegertracing/opentelemetry-cpp/third_party/ms-gsl/include/gsl/gsl_util

   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_UTIL_H
  18 #define GSL_UTIL_H
  19
  20 #include <gsl/gsl_assert> // for Expects
  21
  22 #include <array>
  23 #include <cstddef>          // for ptrdiff_t, size_t
  24 #include <initializer_list> // for initializer_list
  25 #include <type_traits>      // for is_signed, integral_constant
  26 #include <utility>          // for exchange, forward
  27
  28 #if defined(_MSC_VER) && !defined(__clang__)
  29
  30 #pragma warning(push)
  31 #pragma warning(disable : 4127) // conditional expression is constant
  32
  33 #endif            // _MSC_VER
  34
  35 #if defined(__cplusplus) && (__cplusplus >= 201703L)
  36 #define GSL_NODISCARD [[nodiscard]]
  37 #else
  38 #define GSL_NODISCARD
  39 #endif // defined(__cplusplus) && (__cplusplus >= 201703L)
  40
  41 namespace gsl
  42 {
  43 //
  44 // GSL.util: utilities
  45 //
  46
  47 // index type for all container indexes/subscripts/sizes
  48 using index = std::ptrdiff_t;
  49
  50 // final_action allows you to ensure something gets run at the end of a scope
  51 template <class F>
  52 class final_action
  53 {
  54 public:
  55     static_assert(!std::is_reference<F>::value && !std::is_const<F>::value && !std::is_volatile<F>::value, "Final_action should store its callable by value");
  56
  57     explicit final_action(F f) noexcept : f_(std::move(f)) {}
  58
  59     final_action(final_action&& other) noexcept : f_(std::move(other.f_)), invoke_(std::exchange(other.invoke_, false)) {}
  60
  61     final_action(const final_action&) = delete;
  62     final_action& operator=(const final_action&) = delete;
  63     final_action& operator=(final_action&&) = delete;
  64
  65     GSL_SUPPRESS(f.6) // NO-FORMAT: attribute // terminate if throws
  66     ~final_action() noexcept
  67     {
  68         if (invoke_) f_();
  69     }
  70
  71 private:
  72     F f_;
  73     bool invoke_{true};
  74 };
  75
  76 // finally() - convenience function to generate a final_action
  77 template <class F>
  78 GSL_NODISCARD final_action<typename std::remove_cv<typename std::remove_reference<F>::type>::type> finally(F&& f) noexcept
  79 {
  80     return final_action<typename std::remove_cv<typename std::remove_reference<F>::type>::type>(std::forward<F>(f));
  81 }
  82
  83 // narrow_cast(): a searchable way to do narrowing casts of values
  84 template <class T, class U>
  85 GSL_SUPPRESS(type.1) // NO-FORMAT: attribute
  86 constexpr T narrow_cast(U&& u) noexcept
  87 {
  88     return static_cast<T>(std::forward<U>(u));
  89 }
  90
  91 //
  92 // at() - Bounds-checked way of accessing builtin arrays, std::array, std::vector
  93 //
  94 template <class T, std::size_t N>
  95 GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
  96 GSL_SUPPRESS(bounds.2) // NO-FORMAT: attribute
  97 constexpr T& at(T (&arr)[N], const index i)
  98 {
  99     Expects(i >= 0 && i < narrow_cast<index>(N));
 100     return arr[narrow_cast<std::size_t>(i)];
 101 }
 102
 103 template <class Cont>
 104 GSL_SUPPRESS(bounds.4) // NO-FORMAT: attribute
 105 GSL_SUPPRESS(bounds.2) // NO-FORMAT: attribute
 106 constexpr auto at(Cont& cont, const index i) -> decltype(cont[cont.size()])
 107 {
 108     Expects(i >= 0 && i < narrow_cast<index>(cont.size()));
 109     using size_type = decltype(cont.size());
 110     return cont[narrow_cast<size_type>(i)];
 111 }
 112
 113 template <class T>
 114 GSL_SUPPRESS(bounds.1) // NO-FORMAT: attribute
 115 constexpr T at(const std::initializer_list<T> cont, const index i)
 116 {
 117     Expects(i >= 0 && i < narrow_cast<index>(cont.size()));
 118     return *(cont.begin() + i);
 119 }
 120
 121 } // namespace gsl
 122
 123 #if defined(_MSC_VER) && !defined(__clang__)
 124
 125 #pragma warning(pop)
 126
 127 #endif // _MSC_VER
 128
 129 #endif // GSL_UTIL_H