Squashed 'third_party/GSL/' content from commit 0cebbd7
Change-Id: Iffb2e32f2f45297ac6d3e82168cd9df4ac5acc2f
git-subtree-dir: third_party/GSL
git-subtree-split: 0cebbd77bfc21acbf1cc05983ad626539eeeb8e0
diff --git a/include/gsl/gsl_assert b/include/gsl/gsl_assert
new file mode 100644
index 0000000..131fa8b
--- /dev/null
+++ b/include/gsl/gsl_assert
@@ -0,0 +1,145 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
+//
+// This code is licensed under the MIT License (MIT).
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef GSL_CONTRACTS_H
+#define GSL_CONTRACTS_H
+
+#include <exception>
+#include <stdexcept> // for logic_error
+
+//
+// Temporary until MSVC STL supports no-exceptions mode.
+// Currently terminate is a no-op in this mode, so we add termination behavior back
+//
+#if defined(_MSC_VER) && defined(_HAS_EXCEPTIONS) && !_HAS_EXCEPTIONS
+#define GSL_MSVC_USE_STL_NOEXCEPTION_WORKAROUND
+#endif
+
+//
+// There are three configuration options for this GSL implementation's behavior
+// when pre/post conditions on the GSL types are violated:
+//
+// 1. GSL_TERMINATE_ON_CONTRACT_VIOLATION: std::terminate will be called (default)
+// 2. GSL_THROW_ON_CONTRACT_VIOLATION: a gsl::fail_fast exception will be thrown
+// 3. GSL_UNENFORCED_ON_CONTRACT_VIOLATION: nothing happens
+//
+#if !(defined(GSL_THROW_ON_CONTRACT_VIOLATION) || defined(GSL_TERMINATE_ON_CONTRACT_VIOLATION) || \
+ defined(GSL_UNENFORCED_ON_CONTRACT_VIOLATION))
+#define GSL_TERMINATE_ON_CONTRACT_VIOLATION
+#endif
+
+#define GSL_STRINGIFY_DETAIL(x) #x
+#define GSL_STRINGIFY(x) GSL_STRINGIFY_DETAIL(x)
+
+#if defined(__clang__) || defined(__GNUC__)
+#define GSL_LIKELY(x) __builtin_expect(!!(x), 1)
+#define GSL_UNLIKELY(x) __builtin_expect(!!(x), 0)
+#else
+#define GSL_LIKELY(x) (!!(x))
+#define GSL_UNLIKELY(x) (!!(x))
+#endif
+
+//
+// GSL_ASSUME(cond)
+//
+// Tell the optimizer that the predicate cond must hold. It is unspecified
+// whether or not cond is actually evaluated.
+//
+#ifdef _MSC_VER
+#define GSL_ASSUME(cond) __assume(cond)
+#elif defined(__GNUC__)
+#define GSL_ASSUME(cond) ((cond) ? static_cast<void>(0) : __builtin_unreachable())
+#else
+#define GSL_ASSUME(cond) static_cast<void>((cond) ? 0 : 0)
+#endif
+
+//
+// GSL.assert: assertions
+//
+
+namespace gsl
+{
+struct fail_fast : public std::logic_error
+{
+ explicit fail_fast(char const* const message) : std::logic_error(message) {}
+};
+
+namespace details
+{
+#if defined(GSL_MSVC_USE_STL_NOEXCEPTION_WORKAROUND)
+
+ typedef void (__cdecl *terminate_handler)();
+
+ inline gsl::details::terminate_handler& get_terminate_handler() noexcept
+ {
+ static terminate_handler handler = &abort;
+ return handler;
+ }
+
+#endif
+
+ [[noreturn]] inline void terminate() noexcept
+ {
+#if defined(GSL_MSVC_USE_STL_NOEXCEPTION_WORKAROUND)
+ (*gsl::details::get_terminate_handler())();
+#else
+ std::terminate();
+#endif
+ }
+
+#if defined(GSL_TERMINATE_ON_CONTRACT_VIOLATION)
+
+ template <typename Exception>
+ [[noreturn]] void throw_exception(Exception&&)
+ {
+ gsl::details::terminate();
+ }
+
+#else
+
+ template <typename Exception>
+ [[noreturn]] void throw_exception(Exception&& exception)
+ {
+ throw std::forward<Exception>(exception);
+ }
+
+#endif
+
+} // namespace details
+} // namespace gsl
+
+#if defined(GSL_THROW_ON_CONTRACT_VIOLATION)
+
+#define GSL_CONTRACT_CHECK(type, cond) \
+ (GSL_LIKELY(cond) ? static_cast<void>(0) \
+ : gsl::details::throw_exception(gsl::fail_fast( \
+ "GSL: " type " failure at " __FILE__ ": " GSL_STRINGIFY(__LINE__))))
+
+#elif defined(GSL_TERMINATE_ON_CONTRACT_VIOLATION)
+
+#define GSL_CONTRACT_CHECK(type, cond) \
+ (GSL_LIKELY(cond) ? static_cast<void>(0) : gsl::details::terminate())
+
+#elif defined(GSL_UNENFORCED_ON_CONTRACT_VIOLATION)
+
+#define GSL_CONTRACT_CHECK(type, cond) GSL_ASSUME(cond)
+
+#endif
+
+#define Expects(cond) GSL_CONTRACT_CHECK("Precondition", cond)
+#define Ensures(cond) GSL_CONTRACT_CHECK("Postcondition", cond)
+
+#endif // GSL_CONTRACTS_H