bsls_platformutil

Detailed Description

DEPRECATED: Provide consistent interface for platform-dependent functionality.

Outline

• Purpose
• Classes
• Macros
• Description
  • Usage
    • Types
    • Functions and Macros

Purpose

Provide consistent interface for platform-dependent functionality.

Deprecated:

Use bsls_alignmentutil , bsls_byteorder , bsls_platform , and bsls_types instead.

Classes

• bsls::PlatformUtil: namespace for platform-neutral type names and API

Macros

• BSLS_PLATFORMUTIL_IS_LITTLE_ENDIAN: flag set on little-endian platforms
• BSLS_PLATFORMUTIL_IS_BIG_ENDIAN: flag set on big-endian platforms
• BSLS_PLATFORMUTIL_HTONS(x): convert 16-bit from host to network byte order
• BSLS_PLATFORMUTIL_HTONL(x): convert 32-bit from host to network byte order
• BSLS_PLATFORMUTIL_NTOHS(x): convert 16-bit from network to host byte order
• BSLS_PLATFORMUTIL_NTOHL(x): convert 32-bit from network to host byte order

See also

bsls_platform, bsls_types

Description

This component provides a namespace for a set of typedefs and functions that provide a stable, portable interface to platform-dependent functionality. In particular, this component supplies portable typenames for signed and unsigned 64-bit integers, and provides compile-time preprocessor macros that characterize the "endian-ness" of the underlying processor on the current platform. Runtime functionality to return the "endian-ness", and to round up to a multiple of the maximum required alignment for the processor, are also provided.

Usage

The following illustrates how some of the types and functions supplied by this component might be used.

Types

bsls::PlatformUtil::Int64 and bsls::PlatformUtil::Uint64 identify the preferred fundamental types denoting signed and unsigned 64-bit integers, respectively:

bsls::PlatformUtil::Uint64 stimulus = 787000000000ULL;

Clients can use these types in the same way as an int. Clients can also mix usage with other fundamental integral types:

bsls::PlatformUtil::Uint64 nationalDebt = 1000000000000ULL;
nationalDebt += stimulus;
 
unsigned int deficitReduction = 1000000000;
nationalDebt -= deficitReduction;
 
std::cout << "National Debt Level: " << nationalDebt << std::endl;

bsls::PlatformUtil::size_type identifies the preferred integral type denoting the number of elements in a container, and the number of bytes in a single block of memory supplied by an allocator. For example, a typical use is as a typedef in an STL container:

class vector {
 
    // ...
 
  public:
    typedef bsls::PlatformUtil::size_type size_type;
 
    // ...
};

Functions and Macros

The functions:

bool bsls::PlatformUtil::isLittleEndian();
bool bsls::PlatformUtil::isBigEndian();

encapsulate the capability of determining whether a machine is big- or little-endian across all supported platforms. In addition, certain compile-time constants are also provided as preprocessor macros to facilitate conditional compilation:

BSLS_PLATFORMUTIL_IS_BIG_ENDIAN
BSLS_PLATFORMUTIL_IS_LITTLE_ENDIAN

These functions and macros are useful for writing platform-independent code, such as a function that converts the bytes in a short to network byte order (which is consistent with big-endian):

short convertToNetworkByteOrder(short input)
    // Return the specified 'input' in network byte order.
{
#ifdef BSLS_PLATFORMUTIL_IS_BIG_ENDIAN
    return input;
#else
    return static_cast<short>(
                            ((input >> 8) & 0xFF) | ((input & 0xFF) << 8));
#endif
}

Note that in the above usage example, either the macros or the functions can be used to test whether a platform is big- or little-endian.

Typedefs
typedef bsls::PlatformUtil	bsls_PlatformUtil

Macro Definition Documentation

BSLS_PLATFORMUTIL__HTONL

#define BSLS_PLATFORMUTIL__HTONL

(

x

)

BSLS_PLATFORMUTIL_HTONL(x)

BSLS_PLATFORMUTIL__HTONS

#define BSLS_PLATFORMUTIL__HTONS

(

x

)

BSLS_PLATFORMUTIL_HTONS(x)

BSLS_PLATFORMUTIL__IS_BIG_ENDIAN

#define BSLS_PLATFORMUTIL__IS_BIG_ENDIAN   BSLS_PLATFORMUTIL_IS_BIG_ENDIAN

BSLS_PLATFORMUTIL__NTOHL

#define BSLS_PLATFORMUTIL__NTOHL

(

x

)

BSLS_PLATFORMUTIL_NTOHL(x)

BSLS_PLATFORMUTIL__NTOHS

#define BSLS_PLATFORMUTIL__NTOHS

(

x

)

BSLS_PLATFORMUTIL_NTOHS(x)

BSLS_PLATFORMUTIL_HTONL

#define BSLS_PLATFORMUTIL_HTONL

(

x

)

(x)

BSLS_PLATFORMUTIL_HTONS

#define BSLS_PLATFORMUTIL_HTONS

(

x

)

(x)

BSLS_PLATFORMUTIL_IS_BIG_ENDIAN

#define BSLS_PLATFORMUTIL_IS_BIG_ENDIAN   BSLS_PLATFORM_IS_BIG_ENDIAN

Deprecated:

Use preprocessor macro BSLS_PLATFORM_IS_BIG_ENDIAN defined in bsls_platform instead.

BSLS_PLATFORMUTIL_NTOHL

#define BSLS_PLATFORMUTIL_NTOHL

(

x

)

(x)

BSLS_PLATFORMUTIL_NTOHS

#define BSLS_PLATFORMUTIL_NTOHS

(

x

)

(x)

Typedef Documentation

bsls_PlatformUtil

typedef bsls::PlatformUtil bsls_PlatformUtil

This alias is defined for backward compatibility.