bdlb_nullopt.h

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/// @file bdlb_nullopt.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// bdlb_nullopt.h                                                     -*-C++-*-
#ifndef INCLUDED_BDLB_NULLOPT
#define INCLUDED_BDLB_NULLOPT
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup bdlb_nullopt bdlb_nullopt
/// @brief  Provide a tag type and constant indicating an empty nullable value.
/// @addtogroup bdl
/// @{
/// @addtogroup bdlb
/// @{
/// @addtogroup bdlb_nullopt
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#bdlb_nullopt-purpose"> Purpose</a>
/// * <a href="#bdlb_nullopt-classes"> Classes </a>
/// * <a href="#bdlb_nullopt-description"> Description </a>
///
/// # Purpose {#bdlb_nullopt-purpose}
/// Provide a tag type and constant indicating an empty nullable value.
///
/// @deprecated  use `bsl::nullopt_t` from `bsl_optional.h` instead.
///
/// # Classes {#bdlb_nullopt-classes}
///
/// -  NullOptType: tag type representing an empty nullable value
/// -  nullOpt:     literal value of type `NullOptType`
///
/// @see  bsl::optional
///
/// # Description {#bdlb_nullopt-description}
/// This component provides a class, `bdlb::NullOptType`, that
/// is a synonym for `bsl::nullopt_t`.
///
/// In addition to the `NullOptType` class type, this component defines a
/// constant, `bdlb::nullOpt`, of type `NullOptType`, which is a synonym for
/// `bsl::nullopt`.
///
/// Please use `bsl::nullopt_t` and `bsl::nullopt` instead of
/// `bdlb::NullOptType` and `bdlb::nullOpt`, respectively.
///
/// @}
/** @} */
/** @} */
 
/** @addtogroup bdl
 * @{
 */
/** @addtogroup bdlb
 * @{
 */
/** @addtogroup bdlb_nullopt
 * @{
 */
 
#include <bslscm_version.h>
 
#include <bsls_compilerfeatures.h>
#include <bsls_deprecatefeature.h>
#include <bsls_keyword.h>
 
#include <bsl_optional.h>
 
 
namespace bdlb {
 
                                // =================
                                // class NullOptType
                                // =================
 
/// This `class` provides an empty tag type so that `bdlb::NullableValue`
/// can be explicitly constructed in or assigned to an empty state.  There
/// are no publicly accessible constructors for this type other than the
/// copy constructor.  In particular, it is not default constructible, nor
/// list-initializable in C++11.
BSLS_DEPRECATE_FEATURE("bdl", "NullOptType", "Use 'bsl::nullopt_t' instead")
typedef bsl::nullopt_t NullOptType;
 
/// Value of type `NullOptType` that serves as a literal value for the empty
/// state of any nullable value.
#if defined(BSLS_COMPILERFEATURES_SUPPORT_INLINE_VARIABLES)
inline constexpr bsl::nullopt_t nullOpt = bsl::nullopt;
#else
extern const bsl::nullopt_t nullOpt;
#endif
 
// ============================================================================
//                  TEMPLATE AND INLINE FUNCTION DEFINITIONS
// ============================================================================
 
}  // close package namespace
 
 
#endif // ! defined(INCLUDED_BDLB_NULLOPT)
 
// ----------------------------------------------------------------------------
// Copyright 2019 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 ----------------------------------
 
/** @} */
/** @} */
/** @} */