# Versioning

All versions are of the tuple (major,minor,patch).

As of Botan 2.0.0, Botan uses semantic versioning. The minor number increases if any feature addition is made. The patch version is used to indicate a release where only bug fixes were applied. If an incompatible API change is required, the major version will be increased.

The library has functions for checking compile-time and runtime versions.

The build-time version information is defined in botan/build.h

`BOTAN_VERSION_MAJOR`

  The major version of the release.

`BOTAN_VERSION_MINOR`

  The minor version of the release.

`BOTAN_VERSION_PATCH`

  The patch version of the release.

`BOTAN_VERSION_DATESTAMP`

  Expands to an integer of the form YYYYMMDD if this is an official release, or 0 otherwise. For instance, 1.10.1, which was released on July 11, 2011, has a BOTAN_VERSION_DATESTAMP of 20110711.

`BOTAN_DISTRIBUTION_INFO`

  New in version 1.9.3.

  A macro expanding to a string that is set at build time using the `--distribution-info` option. It allows a packager of the library to specify any distribution-specific patches. If no value is given at build time, the value is the string “unspecified”.

`BOTAN_VERSION_VC_REVISION`

  New in version 1.10.1.

  A macro expanding to a string that is set to a revision identifier corresponding to the source, or “unknown” if this could not be determined. It is set for all official releases, and for builds that originated from within a git checkout.

The runtime version information, and some helpers for compile time version checks, are included in botan/version.h

std::string `version_string`()

  Returns a single-line string containing relevant information about this build and version of the library in an unspecified format.

uint32_t `version_major`()

  Returns the major part of the version.

uint32_t `version_minor`()

  Returns the minor part of the version.

uint32_t `version_patch`()

  Returns the patch part of the version.

uint32_t `version_datestamp`()

  Return the datestamp of the release (or 0 if the current version is not an official release).

std::string `runtime_version_check`(uint32_t major, uint32_t minor, uint32_t patch)

  Call this function with the compile-time version being built against, eg:

      Botan::runtime_version_check(BOTAN_VERSION_MAJOR, BOTAN_VERSION_MINOR, BOTAN_VERSION_PATCH)

  It will return an empty string if the versions match, or otherwise an error message indicating the discrepancy. This only is useful in dynamic libraries, where it is possible to compile and run against different versions.

`BOTAN_VERSION_CODE_FOR`(maj, min, patch)

  Return a value that can be used to compare versions. The current (compile-time) version is available as the macro BOTAN_VERSION_CODE. For instance, to choose one code path for version 2.1.0 and later, and another code path for older releases:

      #if BOTAN_VERSION_CODE >= BOTAN_VERSION_CODE_FOR(2,1,0)
         // 2.1+ code path
      #else
         // code path for older versions
      #endif