[Development] Proposal: Deprecating platforms in Qt 5.6 that don't support lambda

Thiago Macieira thiago.macieira at intel.com
Fri Feb 20 20:42:55 CET 2015

On Friday 20 February 2015 12:53:24 Matthew Woehlke wrote:
>   for (auto const i : qtEnumerate(map))
> Maybe it would be nice for Qt to provide one or both of these?

Sounds easy enough. Want to give it a try?

Note that this should also work for foreach:

	foreach (const auto i, qtEnumerate(map))

Something like:

template <typename Map>
struct QEnumerateMap : private Map
	struct const_iterator {
		typename Map::iterator i;
		iterator(typename Map::iterator i) : i(i) {}

		// need to return by value
		std::pair<typename Map::key_type, typename Map::value_type>
		value() const
		{ return std::make_pair(i.key(), i.value()); }

	const_iterator begin() const
	{ return iterator(Map::begin()); }
	const_iterator end() const
	{ return iterator(Map::end()); }
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center

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