bslfmt_formatterbool.h

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/// @file bslfmt_formatterbool.h
///
/// The content of this file has been pre-processed for Doxygen.
///
 
 
// bslfmt_formatterbool.h                                             -*-C++-*-
 
#ifndef INCLUDED_BSLFMT_FORMATTERBOOL
#define INCLUDED_BSLFMT_FORMATTERBOOL
 
#include <bsls_ident.h>
BSLS_IDENT("$Id: $")
 
/// @defgroup bslfmt_formatterbool bslfmt_formatterbool
/// @brief  Provide a formatter customization for bool type
/// @addtogroup bsl
/// @{
/// @addtogroup bslfmt
/// @{
/// @addtogroup bslfmt_formatterbool
/// @{
///
/// <h1> Outline </h1>
/// * <a href="#bslfmt_formatterbool-purpose"> Purpose</a>
/// * <a href="#bslfmt_formatterbool-classes"> Classes </a>
/// * <a href="#bslfmt_formatterbool-canonical-header"> Canonical Header </a>
/// * <a href="#bslfmt_formatterbool-description"> Description </a>
///   * <a href="#bslfmt_formatterbool-usage"> Usage </a>
///     * <a href="#bslfmt_formatterbool-example-formatting-a-bool"> Example: Formatting a bool </a>
///
/// # Purpose {#bslfmt_formatterbool-purpose}
/// Provide a formatter customization for bool type
///
/// # Classes {#bslfmt_formatterbool-classes}
///
/// -  bsl::formatter<bool, t_CHAR>: formatter specialization for `bool`
///
/// # Canonical Header {#bslfmt_formatterbool-canonical-header}
/// bsl_format.h
///
/// # Description {#bslfmt_formatterbool-description}
/// This component provides partial specializations of
/// `bsl::formatter` catering for bool type.
///
/// This header is not intended to be included directly.  Please include
/// `<bsl_format.h>` to be able to use the `bsl::formatter` for `bool` type.
///
/// ## Usage {#bslfmt_formatterbool-usage}
///
///
/// In this section we show the intended use of this component.
///
/// ### Example: Formatting a bool {#bslfmt_formatterbool-example-formatting-a-bool}
///
///
/// We do not expect most users of `bsl::format` to interact with this type
/// directly and instead use `bsl::format` or `bsl::vformat`, so this example is
/// necessarily unrealistic.
///
/// Suppose we want to test this formatter's ability to format a boolean with
/// defined alignment and padding.
///
/// @code
///  bslfmt::MockParseContext<char> mpc("*<6s", 1);
///
///  bsl::formatter<bool, char> f;
///  mpc.advance_to(f.parse(mpc));
///
///  bool value = false;
///
///  bslfmt::MockFormatContext<char> mfc(value, 0, 0);
///
///  mfc.advance_to(bsl::as_const(f).format(value, mfc));
///
///  assert("false*" == mfc.finalString());
/// @endcode
///
/// @}
/** @} */
/** @} */
 
/** @addtogroup bsl
 * @{
 */
/** @addtogroup bslfmt
 * @{
 */
/** @addtogroup bslfmt_formatterbool
 * @{
 */
 
#include <bslscm_version.h>
 
#include <bslfmt_formatterbase.h>
#include <bslfmt_formattercharutil.h>
#include <bslfmt_formatterintegralbase.h>
#include <bslfmt_standardformatspecification.h>
 
#include <bslalg_numericformatterutil.h>
 
 
namespace bslfmt {
 
                         // ========================
                         // struct FormatterBool_Imp
                         // ========================
 
/// This type implements the formatter logic specific to the boolean type.
///
/// See @ref bslfmt_formatterbool 
template <class t_CHAR>
struct FormatterBool_Imp : public FormatterIntegralBase<bool, t_CHAR> {
  public:
    // ACCESORS
 
    /// Create string representation of the specified `value`, customized in
    /// accordance with the requested format and the specified `formatContext`,
    /// and copy it to the output that the output iterator of the
    /// `formatContext` points to.
    template <class t_FORMAT_CONTEXT>
    typename t_FORMAT_CONTEXT::iterator format(
                                        bool              value,
                                        t_FORMAT_CONTEXT& formatContext) const;
};
 
}  // close package namespace
 
 
namespace bsl {
// FORMATTER SPECIALIZATIONS
 
                         // ==============================
                         // struct formatter<bool, t_CHAR>
                         // ==============================
 
/// Partial specialization of the `bsl::formatter` template for the type
/// `bool`.
template <class t_CHAR>
struct formatter<bool, t_CHAR>
: BloombergLP::bslfmt::FormatterBool_Imp<t_CHAR> {
};
 
}
 
// ============================================================================
//                            INLINE DEFINITIONS
// ============================================================================
 
 
namespace bslfmt {
 
                         // ------------------------
                         // struct FormatterBool_Imp
                         // ------------------------
 
template <class t_CHAR>
template <class t_FORMAT_CONTEXT>
inline
typename t_FORMAT_CONTEXT::iterator FormatterBool_Imp<t_CHAR>::format(
                                         bool              value,
                                         t_FORMAT_CONTEXT& formatContext) const
{
    typedef StandardFormatSpecification<t_CHAR> Specification;
    typedef bslalg::NumericFormatterUtil        NFUtil;
    typedef FormatterCharUtil<t_CHAR>           CharUtil;
 
    const Specification& parsedSpec = this->specification();
 
    const int  maxPrefixSize = 4;
    char       prefixBuf[maxPrefixSize];
    char      *prefixBegin = prefixBuf;
    char      *prefixEnd = prefixBuf;
 
    // We want to make sure that we have enough space to accommodate any
    // representation of the `value`.  In case of `unsigned char`
    // it should be large enough for binary representation, in case of string
    // we should be able to fit word `false`, which is 5 characters long.
 
    const int maxValueSize =
                      NFUtil::ToCharsMaxLength<unsigned char, 2>::k_VALUE > 5
                          ? NFUtil::ToCharsMaxLength<unsigned char, 2>::k_VALUE
                          : 5;
    t_CHAR     valueBuf[maxValueSize];
    t_CHAR    *valueBegin = valueBuf;
    t_CHAR    *valueEnd = valueBuf;
 
    if (Specification::e_BOOLEAN_STRING == parsedSpec.formatType()) {
        // String representation.
 
        const char *stringRepresentation       = value ? "true" : "false";
        const int   stringRepresentationLength = value ? 4      : 5;
        valueEnd = CharUtil::outputFromChar(
                             stringRepresentation,
                             stringRepresentation + stringRepresentationLength,
                             valueBegin);
    }
    else {
        unsigned char intRepresentation = static_cast<unsigned char>(value);
        prefixEnd = this->formatPrefix(prefixBuf,
                                       maxPrefixSize,
                                       intRepresentation);
        valueEnd = this->formatValue(valueBuf,
                                     maxValueSize,
                                     intRepresentation);
    }
    return this->outputValue(prefixBegin,
                             prefixEnd,
                             valueBegin,
                             valueEnd,
                             formatContext);
}
 
}  // close package namespace
 
 
#endif  // INCLUDED_BSLFMT_FORMATTERBOOL
 
// ----------------------------------------------------------------------------
// Copyright 2023 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 ----------------------------------
 
/** @} */
/** @} */
/** @} */