bslmf_isarithmetic.h

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/// @file bslmf_isarithmetic.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// bslmf_isarithmetic.h                                               -*-C++-*-
#ifndef INCLUDED_BSLMF_ISARITHMETIC
#define INCLUDED_BSLMF_ISARITHMETIC
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup bslmf_isarithmetic bslmf_isarithmetic
/// @brief  Provide a compile-time check for determining arithmetic types.
/// @addtogroup bsl
/// @{
/// @addtogroup bslmf
/// @{
/// @addtogroup bslmf_isarithmetic
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#bslmf_isarithmetic-purpose"> Purpose</a>
/// * <a href="#bslmf_isarithmetic-classes"> Classes </a>
/// * <a href="#bslmf_isarithmetic-description"> Description </a>
///   * <a href="#bslmf_isarithmetic-usage"> Usage </a>
///     * <a href="#bslmf_isarithmetic-example-1-verify-arithmetic-types"> Example 1: Verify Arithmetic Types </a>
///
/// # Purpose {#bslmf_isarithmetic-purpose}
/// Provide a compile-time check for determining arithmetic types.
///
/// # Classes {#bslmf_isarithmetic-classes}
///
/// -  bsl::is_arithmetic: standard meta-function for determining arithmetic types
/// -  bsl::is_arithmetic_v: the result value of `bsl::is_arithmetic`
///
/// @see  bslmf_integralconstant
///
/// # Description {#bslmf_isarithmetic-description}
/// This component defines a meta-function, `bsl::is_arithmetic`
/// and a template variable `bsl::is_arithmetic_v` that represents the result
/// value of the `bsl::is_arithmetic` meta-function, that may be used to query
/// whether a template parameter type is an arithmetic type.
///
/// `bsl::is_arithmetic` meets the requirements of the `is_arithmetic` template
/// defined in the C++11 standard [meta.unary.comp].
///
/// Note that the template variable `is_arithmetic_v` is defined in the C++17
/// standard as an inline variable.  If the current compiler supports the inline
/// variable C++17 compiler feature, `bsl::is_arithmetic_v` is defined as an
/// `inline constexpr bool` variable.  Otherwise, if the compiler supports
/// the variable templates C++14 compiler feature, `bsl::is_arithmetic_v` is
/// defined as a non-inline `constexpr bool` variable.  See
/// `BSLS_COMPILERFEATURES_SUPPORT_INLINE_VARIABLES` and
/// `BSLS_COMPILERFEATURES_SUPPORT_VARIABLE_TEMPLATES` macros in
/// bsls_compilerfeatures component for details.
///
/// ## Usage {#bslmf_isarithmetic-usage}
///
///
/// In this section we show intended use of this component.
///
/// ### Example 1: Verify Arithmetic Types {#bslmf_isarithmetic-example-1-verify-arithmetic-types}
///
///
/// Suppose that we want to assert whether a set of types are arithmetic types.
///
/// Now, we instantiate the `bsl::is_arithmetic` template for these types, and
/// assert the `value` static data member of each instantiation:
/// @code
/// assert(false == bsl::is_arithmetic<int& >::value);
/// assert(false == bsl::is_arithmetic<int *>::value);
/// assert(true  == bsl::is_arithmetic<int  >::value);
/// @endcode
/// Note that if the current compiler supports the variable templates C++14
/// feature then we can re-write the snippet of code above using the
/// `bsl::is_arithmetic_v` variable as follows:
/// @code
/// #ifdef BSLS_COMPILERFEATURES_SUPPORT_VARIABLE_TEMPLATES
///   assert(false == bsl::is_arithmetic_v<int& >);
///   assert(false == bsl::is_arithmetic_v<int *>);
///   assert(true  == bsl::is_arithmetic_v<int  >);
/// #endif
/// @endcode
/// @}
/** @} */
/** @} */
 
/** @addtogroup bsl
 * @{
 */
/** @addtogroup bslmf
 * @{
 */
/** @addtogroup bslmf_isarithmetic
 * @{
 */
 
#include <bslscm_version.h>
 
#include <bslmf_integralconstant.h>
#include <bslmf_isfloatingpoint.h>
#include <bslmf_isintegral.h>
 
#include <bsls_compilerfeatures.h>
#include <bsls_keyword.h>
 
namespace bsl {
 
                         // ====================
                         // struct is_arithmetic
                         // ====================
 
/// This `struct` template implements the `is_arithmetic` meta-function
/// defined in the C++11 standard [meta.unary.comp] to determine if the
/// (template parameter) `t_TYPE` is an arithmetic type.  This `struct`
/// derives from `bsl::true_type` if the `t_TYPE` is an arithmetic type, and
/// from `bsl::false_type` otherwise.
template <class t_TYPE>
struct is_arithmetic
: integral_constant<bool,
                    is_integral<t_TYPE>::value ||
                        is_floating_point<t_TYPE>::value> {
};
 
#ifdef BSLS_COMPILERFEATURES_SUPPORT_VARIABLE_TEMPLATES
/// This template variable represents the result value of the
/// `bsl::is_arithmetic` meta-function.
template <class t_TYPE>
BSLS_KEYWORD_INLINE_VARIABLE constexpr bool is_arithmetic_v =
                                                  is_arithmetic<t_TYPE>::value;
#endif
 
}  // 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 ----------------------------------
 
/** @} */
/** @} */
/** @} */