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POCustom object bad behaviour after std::sort
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  1. POCustom object bad behaviour after std::sort
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    copied!<p>I'm experiencing issues after sorting a std::vector of Elevator, a custom class.</p> <p><strong>Class definition:</strong></p> <pre><code>class Elevator { private: uint16_t m_id; char *m_channel; ElevatorType m_type; public: Elevator(uint16_t id, const char *channel, ElevatorType type); Elevator(const Elevator &amp;other); ~Elevator(); char *ToCString(); bool operator&lt;(const Elevator&amp; rhs) const; static vector&lt;Elevator&gt; *ElevatorsFromWorkbook(const char *path); }; </code></pre> <p><strong>The less operator</strong> is implemented like this:</p> <pre><code>bool Elevator::operator&lt;(const Elevator&amp; rhs) const { return (this-&gt;m_id &lt; rhs.m_id); } </code></pre> <p><strong>ToCString</strong> method is implemented like this:</p> <pre><code>char *Elevator::ToCString() { char *output = (char*)malloc(sizeof(char) * (8+strlen(m_channel))); char type = 'U'; if (m_type == ELEVATOR_TYPE_A) { type = 'A'; } else if (m_type == ELEVATOR_TYPE_G) { type = 'G'; } else if (m_type == ELEVATOR_TYPE_M) { type = 'M'; } sprintf(output,"%d %s %c",m_id,m_channel,type); return output; } </code></pre> <p><strong>Copy constructor:</strong></p> <pre><code>Elevator::Elevator(const Elevator &amp;other) { m_id = other.m_id; m_channel = (char*)malloc(sizeof(char)*(strlen(other.m_channel)+1)); strcpy(m_channel,other.m_channel); m_type = other.m_type; } </code></pre> <p>Example of the issue:</p> <pre><code>std::vector&lt;Elevator&gt; elevators; elevators.push_back(Elevator(4569,"CHANNEL3",ELEVATOR_TYPE_G)); elevators.push_back(Elevator(4567,"CHANNEL3",ELEVATOR_TYPE_G)); printf("%s\n",elevators.at(0).ToCString()); //Prints "4567 CHANNEL1 G" std::sort(elevators.begin(),elevators.end()); printf("%s\n",elevators.at(0).ToCString()); //ISSUE: Prints "4567 4567 ▒#a G" </code></pre> <p>What am I doing wrong? Thanks for your time!</p> <p><strong>Note on compiling:</strong> I'm using Cygwin with these flags: -Wall -Wextra -fno-exceptions -fno-rtti -march=pentium4 -O2 -fomit-frame-pointer -pipe</p>
 

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