New Thoughts over function pointers

Previous works don't relate to function pointers, but reading some documents reading and learning STL functions lets me K Now the pointer of functions are broadly used in functions such as xxx_if (). I Don ' t think it ' s really that difficult, but it really confused me at the beginning point so why does we have a to include Such a useless characteristic in our nicely-organized language.

Functions lists:

Count_if

Find_if

Remove_if

Remove_copy_if

Replace_if

Replace_copy_if

New Thoughts over function pointers