Merge pull request #4186 from Feoramund/fix-4177

Return false if `Small_Array` can't append multiple elements

core/container/small_array/small_array.odin

@@ -139,9 +139,13 @@ clear :: proc "contextless" (a: ^$A/Small_Array($N, $T)) {
 	resize(a, 0)
 }
 
-push_back_elems :: proc "contextless" (a: ^$A/Small_Array($N, $T), items: ..T) {
-	n := copy(a.data[a.len:], items[:])
-	a.len += n
+push_back_elems :: proc "contextless" (a: ^$A/Small_Array($N, $T), items: ..T) -> bool {
+	if a.len + builtin.len(items) <= cap(a^) {
+		n := copy(a.data[a.len:], items[:])
+		a.len += n
+		return true
+	}
+	return false
 }
 
 inject_at :: proc "contextless" (a: ^$A/Small_Array($N, $T), item: T, index: int) -> bool #no_bounds_check {

tests/core/container/test_core_small_array.odin

@@ -35,6 +35,25 @@ test_small_array_inject_at :: proc(t: ^testing.T) {
 	testing.expect(t, slice_equal(small_array.slice(&array), []int { 0, 0, 1, 2, 3, 0, 4, 5, 6, 7, 8, 9, 0 }))
 }
 
+@(test)
+test_small_array_push_back_elems :: proc(t: ^testing.T) {
+	array: small_array.Small_Array(2, int)
+	testing.expect(t, slice_equal(small_array.slice(&array), []int { }))
+	testing.expect(t, small_array.append(&array, 0), "Expected to be able to append to empty small array")
+	testing.expect(t, slice_equal(small_array.slice(&array), []int { 0 }))
+	testing.expect(t, small_array.append(&array, 1, 2) == false, "Expected to fail appending multiple elements beyond capacity of small array")
+	testing.expect(t, small_array.append(&array, 1), "Expected to be able to append to small array")
+	testing.expect(t, slice_equal(small_array.slice(&array), []int { 0, 1 }))
+	testing.expect(t, small_array.append(&array, 1) == false, "Expected to fail appending to full small array")
+	testing.expect(t, small_array.append(&array, 1, 2) == false, "Expected to fail appending multiple elements to full small array")
+	small_array.clear(&array)
+	testing.expect(t, slice_equal(small_array.slice(&array), []int { }))
+	testing.expect(t, small_array.append(&array, 1, 2, 3) == false, "Expected to fail appending multiple elements to empty small array")
+	testing.expect(t, slice_equal(small_array.slice(&array), []int { }))
+	testing.expect(t, small_array.append(&array, 1, 2), "Expected to be able to append multiple elements to empty small array")
+	testing.expect(t, slice_equal(small_array.slice(&array), []int { 1, 2 }))
+}
+
 slice_equal :: proc(a, b: []int) -> bool {
 	if len(a) != len(b) {
 		return false