Should I put many functions into one file? Or, more or less, one function per file?

Question

I love to organize my code, so ideally I want one class per file or, when I have non-member functions, one function per file.

The reasons are:

1. When

Answer 1

One function per file could get messy in my opinion. Imagine if POSIX and ANSI C headers were made the same way.

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

One class per file is a good idea though.