lundi 2 mars 2015

Is there anyway to avoid warning/error template instantiation backtrace?

Spent some time on it and have absolutely no idea if it's possible. Therefore thought I will ask here then. So, is there any clever way of forcing not to print template backtrace when showing warning/error on gcc/clang?


Example:



template<int I = 0, typename = void>
struct warn {
unsigned : I;
};
struct hello_world {};

template<int I>
class a : warn<I, hello_world> {};

template<int I>
class b : a<I>{};

template<int I>
class c : b<I> {};

template<int I>
class d : c<I> {};

int main() {
d<80>{};
}


gives:



test.cpp:3:5: warning: size of anonymous bit-field (80 bits) exceeds size of its type; value will be truncated to 32 bits
unsigned : I;
^
test.cpp:8:11: note: in instantiation of template class 'warn<80, hello_world>' requested here
class a : warn<I, hello_world> {};
^
test.cpp:11:11: note: in instantiation of template class 'a<80>' requested here
class b : a<I>{};
^
test.cpp:14:11: note: in instantiation of template class 'b<80>' requested here
class c : b<I> {};
^
test.cpp:17:11: note: in instantiation of template class 'c<80>' requested here
class d : c<I> {};
^
test.cpp:20:2: note: in instantiation of template class 'd<80>' requested here
d<80>{};
^
1 warning generated.


So, the expected result would be for example:



test.cpp:3:5: warning: size of anonymous bit-field (80 bits) exceeds size of its type; value will be truncated to 32 bits
unsigned : I;
^
test.cpp:8:11: note: in instantiation of template class 'warn<80, hello_world>' requested here
class a : warn<I, hello_world> {};


There is -ftemplate-backtrace-limit=1 -ferror-limit=1, but I was wondering if there is a possibility to do it from the source code.


Why I need such functionality? Well, I'm using concepts simulations via enable-if, but unfortunately I have template conversion operator within my concept construction and can't just return the value and static assert or enable-if it, because the information is not available anymore. Therefore I thought that maybe warning + concept would do the thing. Let's say I will still have the concept and print one line warning with useful stuff and after that disable the function as usual with enable-if.


Aucun commentaire:

Enregistrer un commentaire