Std :: complex in a struct making compilation slow
I noticed that the following code is very slow to compile: (it can't even finish on my computer)
#include <complex>
struct some_big_struct {
std::complex <double> a[1000000][2];
};
some_big_struct a;
int main () {
return 0;
}
Out of curiosity, I've also tried other variations of the code. However, these codes seem to compile very well on my computer:
#include <complex>
struct some_big_struct {
double a[1000000][2];
};
some_big_struct a;
int main () {
return 0;
}
and
#include <complex>
std::complex <double> a[1000000][2];
int main () {
return 0;
}
I wonder if anyone can elaborate on why this is the case. Thank!
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1 answer
During compilation, the default constructor probably works std::complex
, so it can put the initialized values of all array members in the executable file, rather than generate code that executes this loop when the program starts. So it calls the constructor 2 million times during compilation.
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