nicer syntax for range-y stuff

libswan/include/swan/util.h

@@ -50,6 +50,18 @@ Deferred<Func> makeDeferred(Func func) {
 	return Deferred(func);
 }
 
+// Calling begin/end is stupid...
+template<typename T>
+auto callBegin(T &v) {
+	using namespace std;
+	return begin(v);
+}
+template<typename T>
+auto callEnd(T &v) {
+	using namespace std;
+	return end(v);
+}
+
 // Ret can't be a reference, because C++ doesn't support optional<T&>.
 template<typename Ret, typename Func = std::function<std::optional<Ret>()>>
 class Iter {
@@ -113,6 +125,11 @@ auto map(InputIterator first, InputIterator last, Func func) {
 	return Iter<RetT, decltype(l)>(l);
 }
 
+template<typename Range, typename Func>
+auto map(Range &rng, Func func) {
+	return map(callBegin(rng), callEnd(rng), func);
+}
+
 template<typename InputIterator, typename Func>
 auto filter(InputIterator first, InputIterator last, Func pred) {
 	using RetT = std::remove_reference_t<decltype(*first)>;
@@ -135,6 +152,11 @@ auto filter(InputIterator first, InputIterator last, Func pred) {
 	return Iter<RetT, decltype(l)>(l);
 }
 
+template<typename Range, typename Func>
+auto filter(Range &rng, Func func) {
+	return filter(callBegin(rng), callEnd(rng), func);
+}
+
 template<typename InputIterator, typename Func>
 auto mapFilter(InputIterator first, InputIterator last, Func func) {
 	using RetT = std::remove_reference_t<decltype(*func(*first))>;
@@ -157,4 +179,9 @@ auto mapFilter(InputIterator first, InputIterator last, Func func) {
 	return Iter<RetT, decltype(l)>(l);
 }
 
+template<typename Range, typename Func>
+auto mapFilter(Range &rng, Func func) {
+	return mapFilter(callBegin(rng), callEnd(rng), func);
+}
+
 }

libswan/test/util.t.cc

@@ -4,7 +4,7 @@
 
 test("map") {
 	int ints[] = { 100, 200, 300, 400 };
-	auto mapping = Swan::map(std::begin(ints), std::end(ints), [](int i) { return i / 10; });
+	auto mapping = Swan::map(ints, [](int i) { return i / 10; });
 	auto iter = mapping.begin();
 
 	expecteq(*iter, 10); ++iter;
@@ -16,7 +16,7 @@ test("map") {
 
 test("filter") {
 	int ints[] = { 100, 200, 300, 400 };
-	auto filter = Swan::filter(std::begin(ints), std::end(ints), [](int i) { return i == 200 || i == 400; });
+	auto filter = Swan::filter(ints, [](int i) { return i == 200 || i == 400; });
 	auto iter = filter.begin();
 
 	expecteq(*iter, 200); ++iter;
@@ -26,7 +26,7 @@ test("filter") {
 
 test("mapFilter") {
 	float floats[] = { 10.1, 20.2, 30.3 };
-	auto mapfilt = Swan::mapFilter(std::begin(floats), std::end(floats), [](float f) -> std::optional<int> {
+	auto mapfilt = Swan::mapFilter(floats, [](float f) -> std::optional<int> {
 		if ((int)f == 20)
 			return std::nullopt;
 		return (int)f;