Put version number into ctre.hpp

[wolframroesler]

Please add the library's version number to the single-header file (ctre.hpp) so that users can check which version they already have and whether they need to update.

Also, please supply a ctre::version() function (or whatever name you prefer) to make the version number accessible to application programs.

[wolframroesler]

May I suggest using git tag based version number management? The idea is to define the current version number as a git tag, and only as a git tag (no manual editing of the version number in one of the source files). The benefits are:

• Version number is in exactly one place (no risk of inconsistent edits)
• Can check out by version number (like, git checkout 1.2.3)
• git automatically creates "intermediate version numbers" (something like "we are 5 commits after version 1.2.3")

Here's how to do it. First define the current version number as an annotated git tag, e. g.

$ git tag -a 1.2.3

Then, modify the build framework to put the following line into the appropriate place of ctre.hpp when building it:

auto version() { return "XXX"; }

where XXX is the output of git describe --dirty --always. For example, ctre.hpp would contain something like:

auto version() { return "1.2.3"; }

The nice thing is that the version number will automatically go up as you add new commits, even if you don't create a new tag. For example, after seven commits, the version number will be something like:

auto version() { return "1.2.3-7-gabcde"; }

where abcde is the commit ID. You can return to that exact version later with git checkout abcde. Also, if you changed something but didn't commit it yet, the version number will be something like

auto version() { return "1.2.3-7-gabcde-dirty"; }

indicating that this was built from a "dirty" working tree, and this exact version may not be recoverable from the repository later.

Then, when you release a new version, you simply do git tag -a 1.2.4, and you'll automatically get

auto version() { return "1.2.4"; }

without further ado.

I've been using this tag-based version number management in my production system for some time and find it really convenient. Here's how I do it in a C++ project: https://gitlab.com/wolframroesler/version Maybe you'll find this useful.