#include <stdio.h>

union FLOATUN{
	unsigned int a;
	float b;
};
int main(){
	FLOATUN fun;

	fun.b = 12.34;
	printf("c:%x\n",fun.a);

	double a = 12.34;
	fun.b = (float) a;
	printf("c:%x\n",fun.a);
}

c:414570a4
c:414570a4