bslstl_isconvertibletocstring.h

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/// @file bslstl_isconvertibletocstring.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// bslstl_isconvertibletocstring.h                                   -*-C++-*-
#ifndef INCLUDED_BSLSTL_ISCONVERTIBLETOCSTRING
#define INCLUDED_BSLSTL_ISCONVERTIBLETOCSTRING
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup bslstl_isconvertibletocstring bslstl_isconvertibletocstring
/// @brief  Provide a compile-time check for types convertible to C-string.
/// @addtogroup bsl
/// @{
/// @addtogroup bslstl
/// @{
/// @addtogroup bslstl_isconvertibletocstring
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#bslstl_isconvertibletocstring-purpose"> Purpose</a>
/// * <a href="#bslstl_isconvertibletocstring-classes"> Classes </a>
/// * <a href="#bslstl_isconvertibletocstring-description"> Description </a>
///   * <a href="#bslstl_isconvertibletocstring-usage"> Usage </a>
///     * <a href="#bslstl_isconvertibletocstring-example-1-determine-if-a-type-is-convertible-to-a-c-string"> Example 1: Determine If a Type Is Convertible to a C-String </a>
///
/// # Purpose {#bslstl_isconvertibletocstring-purpose}
/// Provide a compile-time check for types convertible to C-string.
///
/// # Classes {#bslstl_isconvertibletocstring-classes}
///
/// -  bslstl::IsConvertibleToCString: meta-function for C-string convertibility
///
/// @see  bslmf_isconvertible, bslstl_isconvertibletostringview
///
/// # Description {#bslstl_isconvertibletocstring-description}
/// This component provides a meta-function,
/// `bslstl::IsConvertibleToCString`, that may be used to query (at
/// compile-time) whether a type is convertible to a C-string (i.e.,
/// `const CHAR_TYPE *`).
///
/// `bslstl::IsConvertibleToCString` meets the requirements of the
/// `UnaryTypeTrait` concept defined in the C++ standard [meta.rqmts] with a
/// base characteristic of `bsl::true_type` if the (template parameter) `TYPE`
/// is convertible to `const CHAR_TYPE *`, and a base characteristic of
/// `bsl::false_type` otherwise.
///
/// ## Usage {#bslstl_isconvertibletocstring-usage}
///
///
/// In this section we show the intended use of this component.
///
/// ### Example 1: Determine If a Type Is Convertible to a C-String {#bslstl_isconvertibletocstring-example-1-determine-if-a-type-is-convertible-to-a-c-string}
///
///
/// Suppose that we want to determine whether various types are convertible to
/// C-strings (null-terminated character arrays).
///
/// First, we create a type that is convertible to `const char *`:
/// @code
/// struct MyCStringWrapper {
///     const char *d_str;
///     operator const char *() const { return d_str; }
/// };
/// @endcode
/// Now, we instantiate the `bslstl::IsConvertibleToCString` template for
/// various types and verify the results:
/// @code
/// assert( (bslstl::IsConvertibleToCString<char, const char *>::value));
/// assert( (bslstl::IsConvertibleToCString<char, MyCStringWrapper>::value));
/// assert(!(bslstl::IsConvertibleToCString<char, int>::value));
/// assert(!(bslstl::IsConvertibleToCString<char, void *>::value));
/// @endcode
/// @}
/** @} */
/** @} */
 
/** @addtogroup bsl
 * @{
 */
/** @addtogroup bslstl
 * @{
 */
/** @addtogroup bslstl_isconvertibletocstring
 * @{
 */
 
#include <bslscm_version.h>
 
#include <bslmf_integralconstant.h>
#include <bslmf_isconvertible.h>
 
 
namespace bslstl {
 
                      // ==============================
                      // struct IsConvertibleToCString
                      // ==============================
 
/// This `struct` template implements a meta-function to determine if the
/// (template parameter) `t_TYPE` is convertible to `const t_CHAR_TYPE *`.
template <class t_CHAR_TYPE, class t_TYPE>
struct IsConvertibleToCString
: bsl::is_convertible<t_TYPE, const t_CHAR_TYPE *> {
};
 
/// This partial specialization of `IsConvertibleToCString` is instantiated
/// when `const t_CHAR_TYPE (&)[]` (an unbounded array reference) is tested
/// for convertibility to `const t_CHAR_TYPE *`.  This handles edge cases
/// with certain compilers where `bsl::is_convertible` may not correctly
/// handle incomplete array types.
template <class t_CHAR_TYPE>
struct IsConvertibleToCString<t_CHAR_TYPE, const t_CHAR_TYPE (&)[]>
: bsl::true_type {
};
 
}  // close package namespace
 
 
#endif
 
// ----------------------------------------------------------------------------
// Copyright 2026 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 ----------------------------------
 
/** @} */
/** @} */
/** @} */