Compiler directives: #if, #else, #endif

Syntax

#if constexpr
statements
[#else
statements]
[#endif]

Parameters

constexpr - constant integer expression.

Also can be a global variable of type int.
Also can be a user-defined function that returns int. It is executed while compiling, in QM main thread.
Expression with operators is evaluated from left to right, regardless of operator priority.

statements - any statements.

Remarks

If value of constexpr is not 0, are compiled statements after #if and skipped statements after #else. Otherwise, are skipped statements after #if and compiled statements after #else.

Unlike if, compiler directives are evaluated only at compile time.

If #endif is omitted, are compiled (or skipped) all following statements until the end.

QM 2.4.1. #if/#ifdef/#ifndef can be nested in other #if/#ifdef/#ifndef or #else code block. Also now most directives can be tab-indented.

Example

def TEST 5
#if !TEST
out "TEST is 0"
#else
rep 2
	#if TEST>=5
	out "TEST is >= 5"
	#else
	out "TEST is < 5"
	#endif
#endif