#define MDL_STR(SYM) #SYM

Was macht das Ding?

Each # preprocessing token in the replacement list for a function-like macro shall be followed by a parameter as the next preprocessing token in the replacement list.

wird zu

f("hallo");

MDL_STR(int) -> "int"

Falsches Forum.

Falsches Forum.

Wieso? Bietet C++ eine moderne Alternative zu #-Makros?

Ich finde zu C++ gehoert auch C und deswegen sollte man hier schon auch mal C spezifische Fragen stellen koennen - ansonsten besteht die Gefahr, dass man im C-Forum mit irgendwelchem C-Zeug zugebombt wird anstatt eine Loesung fuer C++ zu bekommen.

...

Jaja, red keinen Blödsinn.
Das ist der C99-Präprozessor, der gehört ins C-Forum. Basta. Die Frage war klar und offensichtlich, nicht so, als hätte sie potenziell etwas mit C++ am Hut.

Jaja, red keinen Blödsinn.
Das ist der C99-Präprozessor

self-owned

Sone schrieb:

Jaja, red keinen Blödsinn.
Das ist der C99-Präprozessor

self-owned

N3337 16.3.2 (The # operator) schrieb:

1. Each # preprocessing token in the replacement list for a function-like macro shall be followed by a parameter
as the next preprocessing token in the replacement list.
2. A character string literal is a string-literal with no prefix. If, in the replacement list, a parameter is
immediately preceded by a # preprocessing token, both are replaced by a single character string literal
preprocessing token that contains the spelling of the preprocessing token sequence for the corresponding
argument. Each occurrence of white space between the argument’s preprocessing tokens becomes a single
space character in the character string literal. White space before the first preprocessing token and after
the last preprocessing token comprising the argument is deleted. Otherwise, the original spelling of each
preprocessing token in the argument is retained in the character string literal, except for special handling
for producing the spelling of string literals and character literals: a \ character is inserted before each " and
\ character of a character literal or string literal (including the delimiting " characters). If the replacement
that results is not a valid character string literal, the behavior is undefined. The character string literal
corresponding to an empty argument is "". The order of evaluation of # and ## operators is unspecified.

N1256 6.10.3.2 (The # operator) schrieb:

1. Each # preprocessing token in the replacement list for a function-like macro shall be
followed by a parameter as the next preprocessing token in the replacement list.
Semantics
2. If, in the replacement list, a parameter is immediately preceded by a # preprocessing
token, both are replaced by a single character string literal preprocessing token that
contains the spelling of the preprocessing token sequence for the corresponding
argument. Each occurrence of white space between the argument’s preprocessing tokens
becomes a single space character in the character string literal. White space before the
first preprocessing token and after the last preprocessing token composing the argument
is deleted. Otherwise, the original spelling of each preprocessing token in the argument
is retained in the character string literal, except for special handling for producing the
spelling of string literals and character constants: a \ character is inserted before each "
and \ character of a character constant or string literal (including the delimiting "
characters), except that it is implementation-defined whether a \ character is inserted
before the \ character beginning a universal character name. If the replacement that
results is not a valid character string literal, the behavior is undefined. The character
string literal corresponding to an empty argument is "". The order of evaluation of # and
## operators is unspecified.

Ich hab die gleichen Teile mal Fett gemacht.
...
Ich bin sicher, der C99-Standard hat alles vom C++-Standard genommen

Fakt ist, dass es # schon in C90 gab und in C++ immer noch gibt. Ergo ist es nicht der C99-Präprozessor => Blödsinn.

Wie du meinst.

Die Frage des TEs wurde jetzt ja ohnehin beantwortet.