Globally suppress c ++ std :: cout when testing
I have a Struct point for numeric data using the returnNext () method that returns AND to stdout the next anchor point called each time. I also have a series of unit tests that use this method: in these tests, I want to suppress all std :: cout data so that I can validate the return values without bloating the screen with messages. eg.
struct Data {
Data(int n): datum{n} {};
int datum;
int returnNext() {
std::cout << datum << " returned" << std::endl;
return datum;
}
}
// main.cpp
int main() {
Data d{100};
d.returnNext(); // I want this to print at the screen
return 0;
}
// test.cpp
int main() {
TEST( ... ) {
Data d{100};
ASSERT_THAT(d.returnNext(), 100); // I want just to check the output, not to check
}
std::cout << "some message" << std::endl; // I want this printed
return 0;
}
An obvious solution would be to use flags / commands before the compiler to exclude std :: cout from the TEST build. But that would require editing multiple modules and would also make my code ugly.
Another case would be using redirect stdout for dev / null from the console, but this will also suppress stdout in my test units.
Isn't there a way to programmatically suppress / redirect stdout at specific points in a program's lifetime?
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For a general suppression problem, std::cout
you can use std::basic_ios::rdbuf
with a null buffer:
std::cout.rdbuf(nullptr);
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This is why having hard-coded stdout output in your member functions is a bad idea. Now you think you need to block std::cout
globally because the behavior of your class is inflexible.
Instead, move the call to std::cout
someplace else (to make its use optional) or let it be arbitrary std::ostream
, which you can do nowhere.
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