Parent topic: The preprocessor
Programming tools / The preprocessor

Concatenation operator

Concatenates two parameters of a preprocessor macro.

Syntax

token1 ## token2
  1. token1 is a parameter of the macro or a simple token.
  2. token2 is a parameter of the macro or a simple token.

Usage

The double-sharp operator ## can be used to merge two tokens while expanding a macro and create a single token.

All tokens can not be merged. Usually these tokens are identifiers, or numbers.

The concatenation result produces an identifier.

Source: File A
&define COMMAND(NAME) #NAME, NAME ## _command 
COMMAND(quit)
Result:
& 1 "A"

"quit", quit_command
Parent topic: The preprocessor