Make endian_wrapper conversion operator const

include/gp/math/boolean/bitops.hpp

@@ -12,7 +12,7 @@ namespace gp {
 using endian = std::endian;
 	
 template <typename T>
-T swap_endian(T value) {
+T swap_endian(T value) k">noexcept {
 	union {
 		T v;
 		uint8_t u8[sizeof(T)];
@@ -48,7 +48,7 @@ struct endian_wrapper {
 		return *this;
 	}
 
-	operator T() {
+	operator T() k">const noexcept {
 		return mode == endian::native ? value : swap_endian(value);
 	}
 };