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POHow to resize array of struct elements
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  1. POHow to resize array of struct elements
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    copied!<p>I'm writing a program, where I have one class, inside that class ( or outside, hope it doesn't matter ) I have struct. In that class I need to make an array of struct elements ( I know I can use vector e.g. but in program it is only permitted to use simple dynamic arrays ). </p> <p>I declare an array as <code>T * arr[SIZE]</code>, where <code>T</code> is my struct. The only problem is I don't know exact size of array and need to increase it size if necessary. So I wrote function to resize it:</p> <pre><code>if( some cond ){ T * tmpArr[newSIZE]; memcpy( tmp, db, newSIZE*sizeof(T)); delete [] arr; arr = tmpArr; } </code></pre> <p>But I'm getting a error that <code>MyClass::T[....]</code> is incompatible with <code>MyClass::T*[SIZE]</code> which responds to my <code>arr = tmpArr</code> expression I guess.</p> <p>Can you tell me what I'm doing wrong? And how is better to declare <code>T * arr[size]</code> or <code>T * arr = new T[size]</code> and how do I resize ( and free memory from old one ) array in that case? </p> <p>UPDATE:</p> <p>Thanks for answers, I did accordingly in my program:</p> <pre><code> T * tmp = new T[newSIZE]; memcpy( tmp, db, newSIZE*sizeof(T) ); delete [] db; db = tmp; </code></pre> <p>And now I'm getting weird things, after deleting db and assigning <code>db</code> to <code>tmp</code> I try to print all data contained in db ( or tmp ), that weird thing I get:</p> <pre><code> Smith2 Michigan ave▒ ACME, Ltd. One ACME roa▒ Smit▒ Michigan ave` ACME, Ltd. One ACME roa " One ACME road#@"▒▒▒▒Michigan ave`▒▒▒▒Smit▒" ▒▒ ▒8 Ltd.#Michigan avenuemith4▒aF▒ </code></pre> <p>If I print same data before deleting and assigning, I'll get normal text I want. And after in program ( as I didn't have before and maybe that's problem with my code, I get Segmentation fault ). By the way, I'm using <code>struct</code> of <code>std::string</code> and cygwin in my windows. Do you have any idea what's the problem here?</p>
 

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