This section describes the concatenation symbols "?", which are used to link strings in macros.
The concatenation "?" concatenates one character or one character string to another within a macro body. |
The symbols before and after the concatenation symbol "?" in the symbols of a macro definition can be recognized as formal parameters or local symbols, and concatenation symbols can also be used as delimiter symbols. At macro expansion, formal parameters or local symbols before and after "?" in the symbols are evaluated before they are concatenated in the symbols. |