bslmf_ispair.h

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/// @file bslmf_ispair.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// bslmf_ispair.h                                                     -*-C++-*-
#ifndef INCLUDED_BSLMF_ISPAIR
#define INCLUDED_BSLMF_ISPAIR
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup bslmf_ispair bslmf_ispair
/// @brief  Provide a compile-time check for the bsl::pair type.
/// @addtogroup bsl
/// @{
/// @addtogroup bslmf
/// @{
/// @addtogroup bslmf_ispair
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#bslmf_ispair-purpose"> Purpose</a>
/// * <a href="#bslmf_ispair-classes"> Classes </a>
/// * <a href="#bslmf_ispair-description"> Description </a>
///   * <a href="#bslmf_ispair-usage-notes"> Usage notes </a>
///
/// # Purpose {#bslmf_ispair-purpose}
/// Provide a compile-time check for the bsl::pair type.
///
/// # Classes {#bslmf_ispair-classes}
///
/// -  bslmf::IsPair: meta-function for determining the bsl::pair type.
///
/// @see 
///
/// # Description {#bslmf_ispair-description}
/// This component defines a simple template structure used to
/// evaluate whether it's parameter is a `bsl::pair` type.  A `t_TYPE` that has
/// this trait fulfills the following requirements, where `mX` is a modifiable
/// object and `X` a non-modifiable object of `t_TYPE`:
/// @code
/// Valid expression     Type
/// ----------------     ----
/// t_TYPE::first_type
/// t_TYPE::second_type
///
/// mX.first             first_type
/// mX.second            second_type
/// X.first              const first_type
/// X.second             const second_type
/// @endcode
/// Note that `first` and `second` are *not* member functions, but data members.
///
/// ## Usage notes {#bslmf_ispair-usage-notes}
///
///
/// The `bslmf::IsPair` trait is not used to construct pair objects, as a pair
/// behaves like any other type w.r.t. the constructors and `bslma::Allocator`.
/// Nevertheless, it is used for different purposes in libraries that depend on
/// `bslalg`.  For instance, some libraries use it for printing (a pair does not
/// have a printing method, but it is possible to use the trait to forward the
/// call to `print` to its two members if they both have the printable trait).
/// @}
/** @} */
/** @} */
 
/** @addtogroup bsl
 * @{
 */
/** @addtogroup bslmf
 * @{
 */
/** @addtogroup bslmf_ispair
 * @{
 */
 
#include <bslscm_version.h>
 
#include <bslmf_integralconstant.h>
 
 
 
namespace bslmf {
 
template <class t_TYPE>
struct IsPair : bsl::false_type {};
 
}  // close package namespace
 
 
#endif
 
// ----------------------------------------------------------------------------
// Copyright 2013 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 ----------------------------------
 
/** @} */
/** @} */
/** @} */