Standard Template Library Programmer's Guide

Map has the important property that inserting a new element into a map does not invalidate iterators that point to existing elements. Erasing an element from a map also does not invalidate any iterators, except, of course, for iterators that actually point to the element that is being erased.

struct ltstr {

bool operator()(const char* s1, const char* s2) const {

return strcmp(s1, s2) < 0;

}

};

int main() {

map months;

months["january"] = 31;

months["february"] = 28;

months["march"] = 31;

months["april"] = 30;

months["may"] = 31;

months["june"] = 30;

months["july"] = 31;

months["august"] = 31;

months["september"] = 30;

months["october"] = 31;

months["november"] = 30;

months["december"] = 31;

cout << "june –> " << months["june"] << endl;

map::iterator cur = months.find("june");

map::iterator prev = cur;

map::iterator next = cur;

++next;

--prev;

cout << "Previous (in alphabetical order) is " << (*prev).first << endl;

cout << "Next (in alphabetical order) is " << (*next).first << endl;

}

Defined in the standard header map, and in the nonstandard backward-compatibility header map.h.

Unique Sorted Associative Container, Pair Associative Container

• Data is Assignable.

• Compare is a Strict Weak Ordering whose argument type is Key .

• Alloc is an Allocator.

None.

These members are not defined in the Unique Sorted Associative Container and Pair Associative Container requirements, but are unique to map :