bslmf_isconvertibletoany.h

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/// @file bslmf_isconvertibletoany.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// bslmf_isconvertibletoany.h                                         -*-C++-*-
#ifndef INCLUDED_BSLMF_ISCONVERTIBLETOANY
#define INCLUDED_BSLMF_ISCONVERTIBLETOANY
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup bslmf_isconvertibletoany bslmf_isconvertibletoany
/// @brief  Provide a compile-time check for types convertible to any type.
/// @addtogroup bsl
/// @{
/// @addtogroup bslmf
/// @{
/// @addtogroup bslmf_isconvertibletoany
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#bslmf_isconvertibletoany-purpose"> Purpose</a>
/// * <a href="#bslmf_isconvertibletoany-classes"> Classes </a>
/// * <a href="#bslmf_isconvertibletoany-description"> Description </a>
///   * <a href="#bslmf_isconvertibletoany-usage"> Usage </a>
///     * <a href="#bslmf_isconvertibletoany-example-1-determine-if-a-class-has-a-template-conversion-operator"> Example 1: Determine If a Class Has a Template Conversion Operator </a>
///
/// # Purpose {#bslmf_isconvertibletoany-purpose}
/// Provide a compile-time check for types convertible to any type.
///
/// # Classes {#bslmf_isconvertibletoany-classes}
///
/// -  bslmf::IsConvertibleToAny: meta-function for detecting conversion
///
/// @see  bslmf_isconvertible, bslmf_integralconstant
///
/// # Description {#bslmf_isconvertibletoany-description}
/// This component provides a meta-function,
/// `bslmf::IsConvertibleToAny`, that may be used to query (at compile-time)
/// whether a type has a templatized conversion operator allowing it to be
/// converted to any other type.
///
/// ## Usage {#bslmf_isconvertibletoany-usage}
///
///
/// In this section we show the intended use of this component.
///
/// ### Example 1: Determine If a Class Has a Template Conversion Operator {#bslmf_isconvertibletoany-example-1-determine-if-a-class-has-a-template-conversion-operator}
///
///
/// Suppose that we want to assert whether a particular type has a template
/// conversion operator.
///
/// First, we define a type with the template conversion operator:
/// @code
/// struct TypeWithTemplateConversion {
///     template <class t_TYPE>
///     operator t_TYPE() {
///         return t_TYPE();
///     }
/// };
/// @endcode
/// Now, we instantiate the `bslmf::IsConvertibleToAny` template for
/// `TypeWithTemplateConversion` and assert the `value` of the instantiation:
/// @code
/// assert(bslmf::IsConvertibleToAny<TypeWithTemplateConversion>::value);
/// @endcode
/// @}
/** @} */
/** @} */
 
/** @addtogroup bsl
 * @{
 */
/** @addtogroup bslmf
 * @{
 */
/** @addtogroup bslmf_isconvertibletoany
 * @{
 */
 
#include <bslscm_version.h>
 
#include <bslmf_integralconstant.h>
#include <bslmf_isconvertible.h>
 
 
 
namespace bslmf {
 
                          // =========================
                          // struct IsConvertibleToAny
                          // =========================
 
/// This class template implements a component-private meta-function to
/// determine if the (template parameter) `t_TYPE` is convertible to any
/// other type.
///
/// See @ref bslmf_isconvertibletoany 
template <class t_TYPE>
class IsConvertibleToAny_Imp {
 
    /// A type convertible to this private type must have a template
    /// conversion operator.
    struct UniqueType {
    };
 
  public:
    /// `type` is defined as `bsl::true_type` if `t_TYPE` is convertible to
    /// `UniqueType` and `bsl::false_type` otherwise.
    typedef typename bsl::is_convertible<t_TYPE, UniqueType>::type type;
};
 
/// This `struct` template implements a meta-function to determine if the
/// (template parameter) `t_TYPE` is convertible to any other type.  This
/// `struct` derives from `bsl::true_type` if `t_TYPE` is convertible to any
/// type, and `bsl::false_type` otherwise.
template <class t_TYPE>
struct IsConvertibleToAny : IsConvertibleToAny_Imp<t_TYPE>::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 ----------------------------------
 
/** @} */
/** @} */
/** @} */