Using rb_require with rb_protect to embed Ruby in C -

i want use rb_require rb_protect, in following example:

int error; rb_protect( (value (*)(value))rb_require, (value) "./test", &error); 

but when compile it, error:

passing argument 1 of ‘rb_protect’ incompatible pointer type [enabled default] /usr/include/ruby-1.9.1/ruby/intern.h:357:7: note: expected ‘value (*)(value)’ argument of type ‘value (*)(value,  value)’ 

after searching on google see how use rb_require rb_protect, tried:

int error; rb_protect( ruby_method_func(rb_require), (value) "./test", &error); 

or

value require_wrap(value arg) { return rb_require("./test"); } /*in main:*/ rb_protect( require_wrap, 0, & error); 

but same error. error doesn't stop compilation binary segfault when launch whereas works without rb_protect.

__edit__

there error in source file. in fact solutions have tested works well:

int error; rb_protect( (value (*)(value))rb_require, (value) "./test", &error); 

or

int error; rb_protect( ruby_method_func(rb_require), (value) "./test", &error); 

or

value require_wrap(value arg) {   return rb_require("./test"); } /*in main:*/ rb_protect( require_wrap, 0, & error); 

thanks

solutions works well:

int error; rb_protect( (value (*)(value))rb_require, (value) "./test", &error); 

or

int error; rb_protect( ruby_method_func(rb_require), (value) "./test", &error); 

or

value require_wrap(value arg) {   return rb_require("./test"); } /*in main:*/ rb_protect( require_wrap, 0, & error);