Simple Help Please

[Matt Cromer]

For some reason, this code:

int ball::collision_detection(obstacle_ball &OBSTACLE, char return_x_or_y)
{
	int distance = std::sqrt( (std::pow( (OBSTACLE.get_obstacle_ball_x_position() - ball_x_position) , 2 )) + (std::pow( (OBSTACLE.get_obstacle_ball_y_position() - ball_y_position) , 2 )) );	
}

is giving me the error

1>------ Build started: Project: ALLEGRO_TEST, Configuration: Debug Win32 ------
1>  main.cpp
1>c:\users\matt cromer\documents\visual studio 2010\projects\allegro_test\allegro_test\ball.h(203): error C2668: 'pow' : ambiguous call to overloaded function
1>          c:\program files (x86)\microsoft visual studio 10.0\vc\include\math.h(497): could be 'double pow(double,int)'
1>          c:\program files (x86)\microsoft visual studio 10.0\vc\include\math.h(535): or       'float pow(float,int)'
1>          c:\program files (x86)\microsoft visual studio 10.0\vc\include\math.h(583): or       'long double pow(long double,int)'
1>          while trying to match the argument list '(int, int)'
1>c:\users\matt cromer\documents\visual studio 2010\projects\allegro_test\allegro_test\ball.h(203): error C2668: 'pow' : ambiguous call to overloaded function
1>          c:\program files (x86)\microsoft visual studio 10.0\vc\include\math.h(497): could be 'double pow(double,int)'
1>          c:\program files (x86)\microsoft visual studio 10.0\vc\include\math.h(535): or       'float pow(float,int)'
1>          c:\program files (x86)\microsoft visual studio 10.0\vc\include\math.h(583): or       'long double pow(long double,int)'
1>          while trying to match the argument list '(int, int)'
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

I'm just trying to use the distance formula for the coordinates of the balls.
All of the variables I am calling are integers... what am I doing wrong?

[yasar11732]

I am also new to c++, but it looks like you need to typecast your first variable into either, double, float or long double in order for it to match one of the overloaded functions.

[Matt Cromer]

Where do I need to typecast? Could you post an example of it real quick?

[yasar11732]

Try it like this:

int ball::collision_detection(obstacle_ball &OBSTACLE, char return_x_or_y)
{
	int distance = std::sqrt( (std::pow((double) (OBSTACLE.get_obstacle_ball_x_position() - ball_x_position) , 2 )) + (std::pow((double) (OBSTACLE.get_obstacle_ball_y_position() - ball_y_position) , 2 )) );	
}

[Matt Cromer]

Ahhh I see, thanks alot.

I was confused, because I thought that the compiler would check the variable types and be like okay, they're good already! And I was confused about the syntax of doing it. I thought it went infront of pow.

Again, thanks alot.

[yasar11732]

I am glad I could help. Also note that, return value will be whatever you cast your first argument to be.