allocator interface (first pass)

std/mem/mem.bro

@@ -0,0 +1,29 @@
+c :: import "@ffi/c"
+
+Allocator :: struct {
+	context ?*mut anyopaque
+	alloc @func(context ?*mut anyopaque, size usize, alignment usize) ?*mut u8
+	free @func(context ?*mut anyopaque, memory ?*mut u8, size usize, alignment usize) void
+}
+
+heap Allocator :: Allocator {
+	context = none,
+	alloc = heap_alloc,
+	free = heap_free,
+}
+
+heap_alloc func(context ?*mut anyopaque, size usize, alignment usize) ?*mut u8 {
+	return ptr_cast(u8, c.malloc(size))
+}
+
+heap_free func(context ?*mut anyopaque, memory ?*mut u8, size usize, alignment usize) void {
+	c.free(memory)
+}
+
+alloc func(allocator Allocator, size usize, alignment usize) ?*mut u8 {
+	return allocator.alloc(allocator.context, size, alignment)
+}
+
+free func(allocator Allocator, memory ?*mut u8, size usize, alignment usize) void {
+	allocator.free(allocator.context, memory, size, alignment)
+}