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Function `object.byKey`

Returns a forward range which will iterate over the keys of the associative array. The keys are returned by reference.


						
				auto byKey(T, K, V)
				(
				

				  T aa
				

				) pure nothrow @nogc @safe;
				

				

				auto byKey(T, K, V)
				(
				

				  T* aa
				

				) pure nothrow @nogc;

If structural changes are made to the array (removing or adding keys), all ranges previously obtained through this function are invalidated. The following example program will dereference a null pointer:

import std.stdio : writeln;

auto dict = ["k1": 1, "k2": 2];
auto keyRange = dict.byKey;
dict.clear;
writeln(keyRange.front);    // Segmentation fault

Parameters

Name	Description
aa	The associative array.

Returns

A forward range referencing the keys of the associative array.

Example

auto dict = [1: "v1", 2: "v2"];
int sum;
foreach (v; dict.byKey)
    sum += v;

writeln(sum); // 3

Authors

Walter Bright, Sean Kelly

License

Boost License 1.0.