Version Information: Cairo: A Vector Graphics Library

- - -

Version Information

Version Information — Compile-time and run-time version checks.

Functions

---- - - - - - - - - - - - - - - - - - - -

#define	-CAIRO_VERSION_ENCODE() -
#define	-CAIRO_VERSION_STRINGIZE() -
-int -	-cairo_version () -
const char * -	-cairo_version_string () -

Types and Values

---- - - - - - - - - - - - - - - - - - - - - - - -

#define	CAIRO_VERSION
#define	CAIRO_VERSION_MAJOR
#define	CAIRO_VERSION_MINOR
#define	CAIRO_VERSION_MICRO
#define	CAIRO_VERSION_STRING

Description

Cairo has a three-part version number scheme. In this scheme, we use -even vs. odd numbers to distinguish fixed points in the software -vs. in-progress development, (such as from git instead of a tar file, -or as a "snapshot" tar file as opposed to a "release" tar file).

- _____ Major. Always 1, until we invent a new scheme.
-/  ___ Minor. Even/Odd = Release/Snapshot (tar files) or Branch/Head (git)
-| /  _ Micro. Even/Odd = Tar-file/git
-| | /
-1.0.0
-

Here are a few examples of versions that one might see.

-Releases
---------
-1.0.0 - A major release
-1.0.2 - A subsequent maintenance release
-1.2.0 - Another major release
- 
-Snapshots
----------
-1.1.2 - A snapshot (working toward the 1.2.0 release)
- 
-In-progress development (eg. from git)
---------------------------------------
-1.0.1 - Development on a maintenance branch (toward 1.0.2 release)
-1.1.1 - Development on head (toward 1.1.2 snapshot and 1.2.0 release)
-

Compatibility

- -The API/ABI compatibility guarantees for various versions are as -follows. First, let's assume some cairo-using application code that is -successfully using the API/ABI "from" one version of cairo. Then let's -ask the question whether this same code can be moved "to" the API/ABI -of another version of cairo. - -Moving from a release to any later version (release, snapshot, -development) is always guaranteed to provide compatibility. - -Moving from a snapshot to any later version is not guaranteed to -provide compatibility, since snapshots may introduce new API that ends -up being removed before the next release. - -Moving from an in-development version (odd micro component) to any -later version is not guaranteed to provide compatibility. In fact, -there's not even a guarantee that the code will even continue to work -with the same in-development version number. This is because these -numbers don't correspond to any fixed state of the software, but -rather the many states between snapshots and releases. - -

Examining the version

- -Cairo provides the ability to examine the version at either -compile-time or run-time and in both a human-readable form as well as -an encoded form suitable for direct comparison. Cairo also provides the -macro CAIRO_VERSION_ENCODE() to perform the encoding. - -

-Compile-time
-------------
-CAIRO_VERSION_STRING   Human-readable
-CAIRO_VERSION          Encoded, suitable for comparison
- 
-Run-time
---------
-cairo_version_string()  Human-readable
-cairo_version()         Encoded, suitable for comparison
-

- -For example, checking that the cairo version is greater than or equal -to 1.0.0 could be achieved at compile-time or run-time as follows: - -

- - - - - - - -

1
-2
-3
-4
-5
-6

##if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 0, 0)
-printf ("Compiling with suitable cairo version: %s\n", %CAIRO_VERSION_STRING);
-##endif
-
-if (cairo_version() >= CAIRO_VERSION_ENCODE(1, 0, 0))
-    printf ("Running with suitable cairo version: %s\n", cairo_version_string ());

- -

Functions

CAIRO_VERSION_ENCODE()

#define             CAIRO_VERSION_ENCODE(major, minor, micro)

This macro encodes the given cairo version into an integer. The numbers -returned by CAIRO_VERSION and cairo_version() are encoded using this macro. -Two encoded version numbers can be compared as integers. The encoding ensures -that later versions compare greater than earlier versions.

Parameters

----- - - - - - - - - - - - - - - - - - -

major	the major component of the version number
minor	the minor component of the version number
micro	the micro component of the version number

Returns

the encoded version.

Since: 1.0

CAIRO_VERSION_STRINGIZE()

#define             CAIRO_VERSION_STRINGIZE(major, minor, micro)

This macro encodes the given cairo version into an string. The numbers -returned by CAIRO_VERSION_STRING and cairo_version_string() are encoded using this macro. -The parameters to this macro must expand to numerical literals.

Parameters

----- - - - - - - - - - - - - - - - - - -

major	the major component of the version number
minor	the minor component of the version number
micro	the micro component of the version number

Returns

a string literal containing the version.

Since: 1.8

cairo_version ()

int
-cairo_version (void);

Returns the version of the cairo library encoded in a single -integer as per CAIRO_VERSION_ENCODE. The encoding ensures that -later versions compare greater than earlier versions.

A run-time comparison to check that cairo's version is greater than -or equal to version X.Y.Z could be performed as follows:

- - - - - - - -

1	if (cairo_version() >= CAIRO_VERSION_ENCODE(X,Y,Z)) {...}

- -

See also cairo_version_string() as well as the compile-time -equivalents CAIRO_VERSION and CAIRO_VERSION_STRING.

Returns

the encoded version.

Since: 1.0

cairo_version_string ()

const char *
-cairo_version_string (void);

Returns the version of the cairo library as a human-readable string -of the form "X.Y.Z".

See also cairo_version() as well as the compile-time equivalents -CAIRO_VERSION_STRING and CAIRO_VERSION.

Returns

a string containing the version.

Since: 1.0

Types and Values

CAIRO_VERSION

#define             CAIRO_VERSION

The version of cairo available at compile-time, encoded using -CAIRO_VERSION_ENCODE().

Since: 1.0

CAIRO_VERSION_MAJOR

#define CAIRO_VERSION_MAJOR USE_cairo_version_OR_cairo_version_string_INSTEAD
-

The major component of the version of cairo available at compile-time.

Since: 1.0

CAIRO_VERSION_MINOR

#define CAIRO_VERSION_MINOR USE_cairo_version_OR_cairo_version_string_INSTEAD
-

The minor component of the version of cairo available at compile-time.

Since: 1.0

CAIRO_VERSION_MICRO

#define CAIRO_VERSION_MICRO USE_cairo_version_OR_cairo_version_string_INSTEAD
-

The micro component of the version of cairo available at compile-time.

Since: 1.0

CAIRO_VERSION_STRING

#define             CAIRO_VERSION_STRING

A human-readable string literal containing the version of cairo available -at compile-time, in the form of "X.Y.Z".

Since: 1.8