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花了一些時間,並完全不知道是否有可能。因此,我想我會在這裏問。那麼,在gcc/clang上顯示警告/錯誤時,是否有強制不打印模板回溯的巧妙方法?有沒有辦法避免警告/錯誤模板實例化回溯?
實施例:
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>{};
}
給出:
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.
所以,預期的結果將是例如:
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> {};
有-ftemplate-回溯極限= 1 - ferror-limit = 1,但我想知道是否有可能從源代碼中做到這一點。
爲什麼我需要這樣的功能?那麼,我通過enable-if使用概念模擬,但不幸的是,我的概念構造中有模板轉換操作符,不能只返回值和靜態斷言或啓用 - 如果它,因爲信息不再可用。所以我認爲也許警告+概念會做到這一點。比方說,我仍然會有這個概念,並用有用的東西打印一行警告,之後用enable-if像往常一樣禁用該函數。