bslstl_badvariantaccess.h

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/// @file bslstl_badvariantaccess.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// bslstl_badvariantaccess.h                                          -*-C++-*-
#ifndef INCLUDED_BSLSTL_BADVARIANTACCESS
#define INCLUDED_BSLSTL_BADVARIANTACCESS
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup bslstl_badvariantaccess bslstl_badvariantaccess
/// @brief  Provide an exception class thrown by `bsl::variant`.
/// @addtogroup bsl
/// @{
/// @addtogroup bslstl
/// @{
/// @addtogroup bslstl_badvariantaccess
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#bslstl_badvariantaccess-purpose"> Purpose</a>
/// * <a href="#bslstl_badvariantaccess-classes"> Classes </a>
/// * <a href="#bslstl_badvariantaccess-description"> Description </a>
///
/// # Purpose {#bslstl_badvariantaccess-purpose}
/// Provide an exception class thrown by `bsl::variant`.
///
/// # Classes {#bslstl_badvariantaccess-classes}
///
/// -  bsl::bad_variant_access: exception type thrown by `bsl::variant`
///
/// @see  bslstl_variant, bslstl_stdexceptionutil
///
/// # Description {#bslstl_badvariantaccess-description}
/// This component provides the `bsl::bad_variant_access` exception
/// class.  This exception is thrown by `bsl::get` when a `bsl::variant` does
/// not contain the requested alternative and `bsl::visit` when a `bsl::variant`
/// does not contain a value.  If `std::variant` is available,
/// `bsl::bad_variant_access` is an alias to `std::bad_variant_access`.
/// @}
/** @} */
/** @} */
 
/** @addtogroup bsl
 * @{
 */
/** @addtogroup bslstl
 * @{
 */
/** @addtogroup bslstl_badvariantaccess
 * @{
 */
 
#include <bslscm_version.h>
 
#include <bsls_exceptionutil.h>
#include <bsls_keyword.h>
#include <bsls_libraryfeatures.h>
 
#include <exception>
 
#ifdef BDE_BUILD_TARGET_EXC
 
#if defined(BSLS_LIBRARYFEATURES_HAS_CPP17_BASELINE_LIBRARY) && \
   !(defined(BSLS_LIBRARYFEATURES_FORCE_ABI_ENABLED) &&         \
    (BSLS_LIBRARYFEATURES_FORCE_ABI_ENABLED < 17))
  #define BSLSTL_BAD_VARIANT_ACCESS_IS_ALIASED                                1
#endif // Has C++17 and not disabled
 
 
#ifdef BSLSTL_BAD_VARIANT_ACCESS_IS_ALIASED
  #include <variant>  // for 'std::bad_variant_access'
#endif  // BSLSTL_BAD_VARIANT_ACCESS_IS_ALIASED
 
namespace bsl {
#ifdef BSLSTL_BAD_VARIANT_ACCESS_IS_ALIASED
using std::bad_variant_access;
#else
                          // ========================
                          // class bad_variant_access
                          // ========================
 
class bad_variant_access : public std::exception {
  public:
    // CREATORS
 
    /// Create a @ref bad_variant_access  object.  
    /// \note Note that  this function is
    /// explicitly user-declared, to make it simple to declare `const`
    /// objects of this type.
    bad_variant_access() BSLS_KEYWORD_NOEXCEPT;
 
    // ACCESSORS
 
    /// Return a pointer to the string literal "bad_variant_access", with a storage duration of the lifetime of the program.  
    /// 
    /// \note Note that   the
    /// caller should *not* attempt to free this memory.  
    /// \note Note that  the
    /// @ref bsls_exceptionutil  macro `BSLS_NOTHROW_SPEC` is deliberately not
    /// used here, as a number of standard libraries declare `what` in the
    /// base `exception` class explicitly with the no-throw specification,
    /// even in a build that may not recognize exceptions.
    const char *what() const BSLS_EXCEPTION_VIRTUAL_NOTHROW
                                                         BSLS_KEYWORD_OVERRIDE;
};
 
// ============================================================================
//                           INLINE DEFINITIONS
// ============================================================================
 
                         // ------------------------
                         // class bad_variant_access
                         // ------------------------
 
inline
bad_variant_access::bad_variant_access() BSLS_KEYWORD_NOEXCEPT
: std::exception()
{
}
 
inline
const char *bad_variant_access::what() const BSLS_EXCEPTION_VIRTUAL_NOTHROW
{
    return "bad_variant_access";
}
#endif  // BSLSTL_BAD_VARIANT_ACCESS_IS_ALIASED
 
}  // close namespace bsl
 
#endif  // BDE_BUILD_TARGET_EXC
#endif
 
// ----------------------------------------------------------------------------
// Copyright 2023 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 ----------------------------------
 
/** @} */
/** @} */
/** @} */