GLSL error: `out' qualifier only valid for function parameters in GLSL 1.10 : <p>My shaders have in/out keywords. But I've got GLSL compile error: <code>'out' qualifier only valid for function parameters in GLSL 1.10</code>. Shaders have <code>#version 330</code> directive. Calling <code>glGetString(GL_SHADING_LANGUAGE_VERSION)</code> returns 3.30. </p>

<p>Here is my project: <code>github.com/wlad031/ssu-coursework-2016</code>. Input folder contains shaders. Main source files are <a href="http://github.com/wlad031/ssu-coursework-2016/blob/master/src/ShaderProgramControl.cpp" rel="nofollow">src/ShaderProgramControl.cpp</a> and <a href="http://github.com/wlad031/ssu-coursework-2016/blob/master/src/Shader.cpp" rel="nofollow">src/Shader.cpp</a>. Where is my mistake?</p>
