bslmf_removecv.h

Go to the documentation of this file.

/// @file bslmf_removecv.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// bslmf_removecv.h                                                   -*-C++-*-
#ifndef INCLUDED_BSLMF_REMOVECV
#define INCLUDED_BSLMF_REMOVECV
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup bslmf_removecv bslmf_removecv
/// @brief  Provide a meta-function for removing top-level cv-qualifiers.
/// @addtogroup bsl
/// @{
/// @addtogroup bslmf
/// @{
/// @addtogroup bslmf_removecv
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#bslmf_removecv-purpose"> Purpose</a>
/// * <a href="#bslmf_removecv-classes"> Classes </a>
/// * <a href="#bslmf_removecv-description"> Description </a>
///   * <a href="#bslmf_removecv-usage"> Usage </a>
///     * <a href="#bslmf_removecv-example-1-removing-the-cv-qualifiers-of-a-type"> Example 1: Removing the CV-Qualifiers of a Type </a>
///
/// # Purpose {#bslmf_removecv-purpose}
/// Provide a meta-function for removing top-level cv-qualifiers.
///
/// # Classes {#bslmf_removecv-classes}
///
/// -  bsl::remove_cv: meta-function for removing top-level cv-qualifiers
/// -  bsl::remove_cv_t: alias to the return type of the meta-function
///
/// @see  bslmf_addcv
///
/// # Description {#bslmf_removecv-description}
/// This component defines a meta-function, `bsl::remove_cv`, and
/// declares a `bsl::remove_cv_t` alias to the return type of the
/// `bsl::remove_cv`, that may be used to remove any top-level cv-qualifiers
/// (`const`-qualifier and `volatile`-qualifier) from a type.
///
/// `bsl::remove_cv` and  `bsl::remove_cv_t` meet the requirements of the
/// `remove_cv` template defined in the C++11 standard [meta.trans.cv].
///
/// ## Usage {#bslmf_removecv-usage}
///
///
/// In this section we show intended use of this component.
///
/// ### Example 1: Removing the CV-Qualifiers of a Type {#bslmf_removecv-example-1-removing-the-cv-qualifiers-of-a-type}
///
///
/// Suppose that we want to remove the cv-qualifiers from a particular type.
///
/// First, we create two `typedef`s -- a `const`-qualified and
/// `volatile`-qualified type (`MyCvType`) and the same type without the
/// cv-qualifiers (`MyType`):
/// @code
/// typedef int                MyType;
/// typedef const volatile int MyCvType;
/// @endcode
/// Now, we remove the cv-qualifiers from `MyCvType` using `bsl::remove_cv` and
/// verify that the resulting type is the same as `MyType`:
/// @code
/// assert(true == (bsl::is_same<bsl::remove_cv<MyCvType>::type,
///                                                           MyType>::value));
/// @endcode
/// Finally, if the current compiler supports alias templates C++11 feature, we
/// remove a `const`-qualified and `volatile`-qualifier from `MyCvType` using
///`bsl::remove_cv_t` and verify that the resulting type is the same as
/// `MyType`:
/// @code
/// #ifdef BSLS_COMPILERFEATURES_SUPPORT_ALIAS_TEMPLATES
///   assert(true ==
///                   (bsl::is_same<bsl::remove_cv_t<MyCvType>, MyType>::value));
/// #endif
/// @endcode
/// Note, that the `bsl::remove_cv_t` avoids the `::type` suffix and `typename`
/// prefix when we want to use the result of the `bsl::remove_cv` meta-function
/// in templates.
/// @}
/** @} */
/** @} */
 
/** @addtogroup bsl
 * @{
 */
/** @addtogroup bslmf
 * @{
 */
/** @addtogroup bslmf_removecv
 * @{
 */
 
#include <bslscm_version.h>
 
#include <bslmf_removeconst.h>
#include <bslmf_removevolatile.h>
 
#include <bsls_compilerfeatures.h>
 
namespace bsl {
 
                         // ================
                         // struct remove_cv
                         // ================
 
/// This `struct` template implements the `remove_cv` meta-function defined
/// in the C++11 standard [meta.trans.cv], providing an alias, `type`, that
/// returns the result.  `type` has the same type as the (template
/// parameter) `t_TYPE` except that any top-level cv-qualifiers have been
/// removed.
///
/// See @ref bslmf_removecv 
template <class t_TYPE>
struct remove_cv {
 
    // PUBLIC TYPES
 
    /// This `typedef` is an alias to the same type as the (template
    /// parameter) `t_TYPE` except that any top-level cv-qualifier has been
    /// removed.
    typedef typename remove_const<typename remove_volatile<t_TYPE>::type>::type
        type;
};
 
#ifdef BSLS_COMPILERFEATURES_SUPPORT_ALIAS_TEMPLATES
 
// ALIASES
 
/// @ref remove_cv_t  is an alias to the return type of the `bsl::remove_cv`
/// meta-function.  Note, that the @ref remove_cv_t  avoids the `::type` suffix
/// and `typename` prefix when we want to use the result of the
/// meta-function in templates.
template <class t_TYPE>
using remove_cv_t = typename remove_cv<t_TYPE>::type;
#endif  // BSLS_COMPILERFEATURES_SUPPORT_ALIAS_TEMPLATES
 
}  // close namespace bsl
 
#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 ----------------------------------
 
/** @} */
/** @} */
/** @} */