Re: Sorting lists by struct member variables
ryan1_00@hotmail.com wrote:
Bascically I want to sort a list by a member variable of a struct
stored in the list.
// ------------------------------
// Struct Header
// ------------------------------
#include <string>
struct Connection {
int order;
std::string url;
int port;
inline bool empty() {
if ( (url.empty()) && (port == 0) ) {
return true;
} else {
return false;
}
}
};
// ------------------------------
// ------------------------------
// main
// ------------------------------
std::list<Connection> lstconn;
Connection conn;
conn.order = 2
conn.url = www.eg2.com
conn.port = 80
lstconn.push_back(conn);
conn.order = 1
conn.url = www.eg.com
conn.port = 80
lstconn.push_back(conn);
// ------------------------------
How do i sort on the order var?
You need to define a comparison functor which will compare two values
of 'Connection' type and return true if the first's 'order' is smaller
than then the other's. Then you sort the list while providing your
comparator. RTFM about the 'sort' member of std::list class.
lstconn.sort() is what i think i want to use but cant see how to point
it at the member var order.
RTFM
And, BTW, what book are you reading that explains how to use different
facilities of the Standard library? Doesn't that book explain how to
provide custom sorters to 'std::sort' or 'std::list::sort'?
V
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