c++ - swap with non-const reference parameters -

i got [error] invalid initialization of non-const reference of type 'float&' rvalue of type 'float'

#include <stdio.h> void swap(float &a, float &b){     float temp=a;     a=b;     b=temp; } main() {     int a=10, b=5;     swap((float)a, (float)b);     printf("%d%d",a,b); } 

vlad correct, why cast float? use int values. however, if have reason doing way, must consistent in cast , references:

#include <stdio.h>  void swap(float *a, float *b){     float temp=*a;     *a=*b;     *b=temp; }  int main() {     int a=10, b=5;     swap((float*)&a, (float*)&b);     printf("\n%d%d\n\n",a,b);     return 0; } 

output:

$ ./bin/floatcast  510 

when pass address function, must take pointer argument. void swap(float *a,.. when need reference address of variable (to pass pointer), use address of operator &. when handle values passed pointer, in order operate on values pointed pointer must dereference pointer using * operator. putting together, code above. (much easier use int... :)

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c++ refernce

if understand want in comment, want this:

#include <iostream>  // using namespace std;  void swap(float& a, float& b){     float temp=a;     a=b;     b=temp; }  int main() {     int a=10, b=5;     swap ((float&)a, (float&)b);     std::cout << std::endl << << b << std::endl << std::endl;     return 0; } 

output:

$ ./bin/floatref  510