Error C2059: syntax error 'constant'

Question

I have the following code in a header file:

enum {false,true};

and I have my main function in main.c. if I change the extention to main.cpp I get the following error:

Error C2059: syntax error 'constant'

Im using visual c++, any Idea why`?

You've found one of the reasons why C++ cannot be made 100% backwards compatible with C. — Gorpik, Sep 04 '13 at 12:52

score 11 · Accepted Answer · answered Sep 04 '13 at 12:48

11

true and false are keywords representing constant values in C++. You cannot use them to name things such as enum values.

As an example, the following would compile

enum { false_, true_ };

int main() {}

answered Sep 04 '13 at 12:48

juanchopanza

It is also true for other constants (enumeration for instance) that are already defined elsewhere (I encountered a problem when I have defined an enumeration value named NO_ERROR which is already defined defined in winerror.h). – Guy Avraham Sep 13 '16 at 12:18

score 1 · Answer 2 · answered Sep 04 '13 at 12:53

1

false and true are reserve words in C++. You can't redefine it as variable.

answered Sep 04 '13 at 12:53

haccks

2 Answers2