don't use std::complex

Author: adamant-pwn

cp-algo/math/fft.hpp

@@ -4,7 +4,6 @@
 #include "../number_theory/modint.hpp"
 #include "../util/complex.hpp"
 #include <algorithm>
-#include <complex>
 #include <cassert>
 #include <ranges>
 #include <vector>

cp-algo/number_theory/two_squares.hpp

@@ -1,13 +1,13 @@
 #ifndef CP_ALGO_NUMBER_THEORY_TWO_SQUARES_HPP
 #define CP_ALGO_NUMBER_THEORY_TWO_SQUARES_HPP
 #include "euler.hpp"
+#include "../util/complex.hpp"
 #include <cassert>
-#include <complex>
 #include <utility>
 #include <vector>
 #include <map>
 namespace cp_algo::math {
-    using gaussint = std::complex<int64_t>;
+    using gaussint = complex<int64_t>;
     gaussint two_squares_prime_any(int64_t p) {
         if(p == 2) {
             return gaussint(1, 1);

cp-algo/util/complex.hpp

@@ -2,6 +2,7 @@
 #define CP_ALGO_UTIL_COMPLEX_HPP
 #include <cmath>
 namespace cp_algo {
+    // Custom implementation, since std::complex is UB on non-floating types
     template<typename T>
     struct complex {
         using value_type = T;