#if

#if is a compile-time if statement. It looks like a normal if statement, except its condition must be resolvable at compile time. This is because it controls whether or not the body of the #if statement are included in the compilation.

Static-ifs can be used inside and outside of procedures.

Outside of Procedures

When outside of a procedure, static-ifs can be used to control whether or not certain symbols are defined in the current compilation.

DEBUG_MODE :: true

#if DEBUG_MODE {
    // This procedure is only defined if DEBUG_MODE is true
    debug_only_procedure :: () {
        // ...
    }
} else {
    // This procedure is only defined if DEBUG_MODE is false
    not_a_debug_procedure :: () {
        
    }
}

Static-ifs can contain any top-level "thing" in the language: procedures, structures, unions, and even #load directives. Using this feature, you can optionally include files depending on a condition.

USE_EXTENSIONS :: false
MINIMUM_EXTENSION_VERSION :: 5

#if USE_EXTENSIONS && MINIMUM_EXTENSION_VERSION >= 3 {
    #load "./extensions/v3"
}

Inside of procedures

When inside a procedure, static-ifs can contain statements that will only be included if the static-if resolves to be true.

DEBUG_MODE :: true

draw :: () {
    #if DEBUG_MODE {
        draw_debug_ui();
    }

    // ...
}

Other uses

See the #defined documentation for more uses of static-if statements.