# File ext/extconf.rb, line 43 def have_constant(name) sname = name.is_a?(Symbol) ? name.to_s : name.upcase checking_for name do src = %{ #include <curl/curl.h> int main() { int test = (int)#{sname}; return 0; } } if try_compile(src,"#{$CFLAGS} #{$LIBS}") define name true else #define name, 0 false end end end