#define COMMA ,
ECHO(template<int COMMA bool>)

有点痛，但很管用.

FWIW，如果参数的语法允许 ()s，则不需要替换，例如，

FWIW, if the syntax for the argument allows ()s, you don't need the substitution, e.g.,

ECHO((a, b))

适用于单个参数宏，但不适用于所有情况(包括您的情况).

will work for a single argument macro but that doesn't work in all cases (including yours).