Recently in learning the game engine development, see the game engine development explained by type of pun on size to transform the way:

 union intWithFloat {
Int32_t m_i32; 
Float m_f32; } 
{float swapFloat32 (float value) 
IntWithFloat I; 
I.m _i32=value; 
I.m _f32=swapInt32 (i.m _i32) 
Return i.m _f32; } 

Small white building Lord, don't understand why this is so complicated that constructing a conversion function to convert float32 why not, using type pun here==what's the meaning?