// bslmf_removecv.h                                                   -*-C++-*-
#ifndef INCLUDED_BSLMF_REMOVECV
#define INCLUDED_BSLMF_REMOVECV

#include <bsls_ident.h>
BSLS_IDENT("$Id: $")

//@PURPOSE: Provide a meta-function for removing top-level cv-qualifiers.
//
//@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_ALSO: bslmf_addcv
//
//@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
///-----
// In this section we show intended use of this component.
//
///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`):
// ```
// typedef int                MyType;
// typedef const volatile int MyCvType;
// ```
// Now, we remove the cv-qualifiers from `MyCvType` using `bsl::remove_cv` and
// verify that the resulting type is the same as `MyType`:
// ```
// assert(true == (bsl::is_same<bsl::remove_cv<MyCvType>::type,
//                                                           MyType>::value));
// ```
// 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`:
// ```
// #ifdef BSLS_COMPILERFEATURES_SUPPORT_ALIAS_TEMPLATES
//   assert(true ==
//                   (bsl::is_same<bsl::remove_cv_t<MyCvType>, MyType>::value));
// #endif
// ```
// 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.

#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.
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

/// `remove_cv_t` is an alias to the return type of the `bsl::remove_cv`
/// meta-function.  Note, that the `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 ----------------------------------
