title: make is calling g++ is always re-compiles even when I do not change the source code
body: <p>I am using make which calls g++ always re-compiles the code, even when I do not change the source code. That happens for all my projects, even for simple ones such as:</p>
  
  <pre><code>    [code]
      all: main.cpp
          g++ -std=c++11 -c main.cpp
      [/code]
  </code></pre>
  
  <p>I believe it should compare the date/time on source and object code. Could some help me with this, I am running using GNU toolchain on Ubuntu 12.04</p>
  
  <p>THX</p>
  
  <p>Edit: sorry guys, I do use Makefile, I edited my question accordingly.</p>