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POhow to pass vector of string to foo(char const *const *const)?
 

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    <p><strong>Edit:</strong> After implementing James Hopkin' suggestion, I still get the warnings of "invalid name 'null'", which is much better than those weird characters. Then, I went back and read the library document again, and it turns out that for that particular function, it's argument should have one more element of non-NULL string than the size of aNames. That additional string has some other purpose. After adding one more string, the code runs fine. It's all my fault, and I am so sorry.</p> <p>Original post:</p> <p>Hi, </p> <p>This is my first post so please be nice. I searched in this forum and googled but I still can not find the answer. This problem has bothered me for more than a day, so please give me some help. Thank you.</p> <p>I need to pass a vector of string to a library function foo(char const *const *const). I can not pass the &amp;Vec[0] since it's a pointer to a string. Therefore, I have an array and pass the c_str() to that array. The following is my code (aNames is the vector of string):</p> <pre><code>const char* aR[aNames.size()]; std::transform(aNames.begin(), aNames.end(), aR, boost::bind(&amp;std::string::c_str, _1)); foo(aR); </code></pre> <p>However, it seems it causes some undefined behavior:</p> <p>If I run the above code, then the function foo throw some warnings about illegal characters ('èI' blablabla) in aR.</p> <p>If I print aR before function foo like this:</p> <pre><code>std::copy(aR, aR+rowNames.size(), std::ostream_iterator&lt;const char*&gt;(std::cout, "\n")); foo(aR); </code></pre> <p>Then, everything is fine. My questions are:</p> <ol> <li><p>Does the conversion causes undefined behavior? If so, why?</p></li> <li><p>What is the correct way to pass vector of string to foo(char const *const *const)?</p></li> </ol>
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