// bdlde_byteorder.h                                                  -*-C++-*-
#ifndef INCLUDED_BDLDE_BYTEORDER
#define INCLUDED_BDLDE_BYTEORDER

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

//@PURPOSE: Provide an enumeration of the set of possible byte orders.
//
//@CLASSES:
//  bdlde::ByteOrder: namespace for a byte order `enum`
//
//@SEE_ALSO: bdlde_charconvertutf16
//
//@DESCRIPTION: This component provides a namespace for the `enum` type
// `bdlde::ByteOrder::Enum`, which enumerates the set of possible byte orders.
//
///Enumerators
///-----------
// ```
// Name              Description
// ---------------   ---------------------------------------------------
// e_LITTLE_ENDIAN   little-endian
// e_BIG_ENDIAN      big-endian
// e_NETWORK         network byte order (aliased to 'e_BIG_ENDIAN')
// e_HOST            aliased to 'e_LITTLE_ENDIAN' or 'e_BIG_ENDIAN' (depending
//                   on platform)
// ```
//
///Usage
///-----
// This section illustrates intended use of this component.
//
///Example 1: Basic Syntax
///- - - - - - - - - - - -
// The following snippets of code provide a simple illustration of
// `bdlde::ByteOrder` usage.
//
// First, we create a variable `value` of type `bdlde::ByteOrder::Enum` and
// initialize it with the enumerator value
// `bdlde::ByteOrder::e_LITTLE_ENDIAN`:
// ```
// bdlde::ByteOrder::Enum value = bdlde::ByteOrder::e_LITTLE_ENDIAN;
// ```
// Next, we store a pointer to its ASCII representation in a variable
// `asciiValue` of type `const char *`:
// ```
// const char *asciiValue = bdlde::ByteOrder::toAscii(value);
// assert(0 == bsl::strcmp(asciiValue, "LITTLE_ENDIAN"));
// ```
// Then, we try one of the aliased identifiers, and we get a string
// corresponding to the value it is aliased to:
// ```
// value      = bdlde::ByteOrder::e_NETWORK;
// asciiValue = bdlde::ByteOrder::toAscii(value);
//
// assert(0 == bsl::strcmp(asciiValue, "BIG_ENDIAN"));
// ```
// Finally, we print `value` to `bsl::cout`:
// ```
// bsl::cout << value << bsl::endl;
// ```
// This statement produces the following output on `stdout`:
// ```
// BIG_ENDIAN
// ```

#include <bdlscm_version.h>

#include <bsls_platform.h>

#include <bsl_iosfwd.h>

namespace BloombergLP {

namespace bdlde {
                              // ================
                              // struct ByteOrder
                              // ================

/// This `struct` provides a namespace for enumerating the set of byte
/// orders.  See `Enum` in the TYPES sub-section for details.
///
/// This class:
/// * supports a complete set of *enumeration* operations
///   - except for `bdex` serialization
/// For terminology see `bsldoc_glossary`.
struct ByteOrder {

  public:
    // TYPES
    enum Enum {
        e_LITTLE_ENDIAN,                // base enumeration
        e_BIG_ENDIAN,                   // base enumeration

        e_NETWORK = e_BIG_ENDIAN,       // Network byte order is always
                                        // aliased to big-endian.

#ifdef BSLS_PLATFORM_IS_LITTLE_ENDIAN
        e_HOST    = e_LITTLE_ENDIAN     // Host byte order is always aliased to
#else                                   // a base enumeration, varying
        e_HOST    = e_BIG_ENDIAN        // depending on the platform.
#endif
    };

  public:
    // CLASS METHODS

    /// Write the string representation of the specified enumeration `value`
    /// to the specified output `stream`, and return a reference to
    /// `stream`.  Optionally specify an initial indentation `level`, whose
    /// absolute value is incremented recursively for nested objects.  If
    /// `level` is specified, optionally specify `spacesPerLevel`, whose
    /// absolute value indicates the number of spaces per indentation level
    /// for this and all of its nested objects.  If `level` is negative,
    /// suppress indentation of the first line.  If `spacesPerLevel` is
    /// negative, format the entire output on one line, suppressing all but
    /// the initial indentation (as governed by `level`).  See `toAscii` for
    /// what constitutes the string representation of a
    /// `ByteOrder::Enum` value.
    static bsl::ostream& print(bsl::ostream& stream,
                               Enum          value,
                               int           level          = 0,
                               int           spacesPerLevel = 4);

    /// Return the non-modifiable string representation corresponding to the
    /// specified enumeration `value`, if it exists, and a unique (error)
    /// string otherwise.  The string representation of `value` matches the
    /// name of its corresponding base enumeration with the "e_" prefix
    /// elided.  For example:
    /// ```
    /// bsl::cout << ByteOrder::toAscii(ByteOrder::e_NETWORK);
    /// ```
    /// will print the following on standard output:
    /// ```
    /// BIG_ENDIAN
    /// ```
    /// Note that specifying a `value` that does not match any of the
    /// enumerators will result in a string representation that is distinct
    /// from any of those corresponding to the enumerators, but is otherwise
    /// unspecified.
    static const char *toAscii(Enum value);
};

// FREE OPERATORS

/// Write the string representation of the specified enumeration `value` to
/// the specified output `stream` in a single-line format, and return a
/// reference to `stream`.  See `toAscii` for what constitutes the string
/// representation of a `bdlde::ByteOrder::Enum` value.  Note that this
/// method has the same behavior as
/// ```
/// bdlde::ByteOrder::print(stream, value, 0, -1);
/// ```
bsl::ostream& operator<<(bsl::ostream& stream, ByteOrder::Enum value);

// ============================================================================
//                        INLINE FUNCTION DEFINITIONS
// ============================================================================

                          // -----------------------
                          // struct bdlde::ByteOrder
                          // -----------------------

}  // close package namespace

// FREE OPERATORS
inline
bsl::ostream& bdlde::operator<<(bsl::ostream&          stream,
                                bdlde::ByteOrder::Enum value)
{
    return ByteOrder::print(stream, value, 0, -1);
}

}  // close enterprise namespace

#endif

// ----------------------------------------------------------------------------
// Copyright 2015 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 ----------------------------------
