bslmf_negation.h

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/// @file bslmf_negation.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// bslmf_negation.h                                                   -*-C++-*-
#ifndef INCLUDED_BSLMF_NEGATION
#define INCLUDED_BSLMF_NEGATION
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup bslmf_negation bslmf_negation
/// @brief  Provide the logical negation (NOT) for type traits.
/// @addtogroup bsl
/// @{
/// @addtogroup bslmf
/// @{
/// @addtogroup bslmf_negation
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#bslmf_negation-purpose"> Purpose</a>
/// * <a href="#bslmf_negation-classes"> Classes </a>
/// * <a href="#bslmf_negation-description"> Description </a>
///
/// # Purpose {#bslmf_negation-purpose}
/// Provide the logical negation (NOT) for type traits.
///
/// # Classes {#bslmf_negation-classes}
///
/// -  bsl::negation: forms the logical NOT of the specified type trait
/// -  bsl::negation_v: the result value of the `negation` meta-function
///
/// # Description {#bslmf_negation-description}
/// This component makes available the functionality provided by
/// the `std::negation` meta-function in all C++ language modes -
/// `std::negation` is available only starting from C++17.
/// @}
/** @} */
/** @} */
 
/** @addtogroup bsl
 * @{
 */
/** @addtogroup bslmf
 * @{
 */
/** @addtogroup bslmf_negation
 * @{
 */
 
#include <bslscm_version.h>
 
#include <bsls_compilerfeatures.h>
#include <bsls_keyword.h>
#include <bsls_libraryfeatures.h>
 
#ifdef BSLS_LIBRARYFEATURES_HAS_CPP17_BASELINE_LIBRARY
#include <type_traits>
#else
#include <bslmf_conditional.h>
#include <bslmf_integralconstant.h>
#endif
 
namespace bsl {
 
#ifdef BSLS_LIBRARYFEATURES_HAS_CPP17_BASELINE_LIBRARY
 
using std::negation;
using std::negation_v;
 
#else
 
                         // ===============
                         // struct negation
                         // ===============
 
template <class B>
struct negation : integral_constant<bool, !bool(B::value)> {
};
 
#ifdef BSLS_COMPILERFEATURES_SUPPORT_VARIABLE_TEMPLATES
template <class B>
BSLS_KEYWORD_INLINE_VARIABLE constexpr bool negation_v = negation<B>::value;
#endif
 
#endif
 
}  // close namespace bsl
 
#endif
 
// ----------------------------------------------------------------------------
// Copyright 2024 Bloomberg Finance L.P.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ----------------------------- END-OF-FILE ----------------------------------
 
/** @} */
/** @} */
/** @} */