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POSegmentation fault while using std::map<std::string, GLuint>!
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  1. POSegmentation fault while using std::map<std::string, GLuint>!
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    copied!<p>I have a Segmentation fault while using <code>std::map&lt;std::string, GLuint&gt;</code> (sic!). There are no visible pointers (where I could do something wrong) there! I don't know how it is possible. It doesn't occur in each place, only in <code>graphical_engine::draw(figure *f)</code> and in few places more (I think). Segmentation fault attacks me when I try to do something like: <code>cached["pos"] = 2</code>, <code>cached.begin()-&gt;first</code> etc.. But, step by step:</p> <p>Firstly I have to note that I'm using in this 'project' C++11. I do not know if that information will be helpful, but...</p> <p>I'm also using SFML library to open a window and write text in it.</p> <p>I am creating some graphic application in OpenGL. I got stuck in place where I created a kind of cache. I want to store in the cache an index of vertex attribute from a shader program. I simply don't want to 'charge' it using <code>glGetAttribLocation</code> more than once (the first time I call <code>glVertexAttribPointer</code> and the second time: use <code>glEnableVertexAttribArray</code>), so I've chose 'caching' it in <code>std::map&lt;std::string, GLuint&gt;</code>.</p> <p>In my application I've written a few classes responsible for: application logics, graphics. In graphics class I declared auxiliary types: <code>shader</code>, <code>shader_program</code>. I am writing it because when I call <code>s.is_cached("pos")</code> in, e.g <code>int main</code>, there is no Segmentation fault. The problem appears when I try to venture to call <code>s.is_cached("pos")</code> in my method <code>void graphics_engine::draw(figure *f)</code>. Then the famous Segmentation fault appears and it is not funny.</p> <p><code>bool shader_program::is_cached(const char *name)</code> implementation looks like:</p> <pre><code>bool shader_program::is_cached(const char *name) { std::string attrname = name; // p like 'pair' for(auto p: cached) { if(p.first == attrname) return true; } return false; } </code></pre> <p>Compilator <code>g++ (...) -std=c++0x</code> with an option <code>-g -D_GLIBCXX_DEBUG</code> produces code which interacts with my gdb and it returns</p> <pre><code>__gnu_debug::_Safe_sequence_base::_M_attach_single (this=0xb7b805c9, __it=0xbffff478, __constant=false) at ../../.././libstdc++-v3/src/debug.cc:274 274 __it-&gt;_M_next-&gt;_M_prior = __it; </code></pre> <p>If you don't understand any of my code, please, post a comment.</p> <p>The full code: <a href="http://jackweb.ovh.org/OGL.zip" rel="nofollow">http://jackweb.ovh.org/OGL.zip</a></p> <p>What causes the segmentation fault?</p>
 

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