format struct pointers as "<typename>@<address>" (#752)

1 files changed, 15 insertions, 1 deletions

diff --git a/std/fmt/index.zig b/std/fmt/index.zig
index b7ae018bdc..a32a6e0295 100644
--- a/std/fmt/index.zig
+++ b/std/fmt/index.zig
@@ -228,7 +228,7 @@ pub fn formatValue(value: var, context: var, output: fn(@typeOf(context), []cons
             if (@typeId(T.Child) == builtin.TypeId.Array and T.Child.Child == u8) {
                 return output(context, (*value)[0..]);
             } else {
-                @compileError("Unable to format type '" ++ @typeName(T) ++ "'");
+                return format(context, output, "{}@{x}", @typeName(T.Child), @ptrToInt(value));
             }
         },
         else => if (@canImplicitCast([]const u8, value)) {
@@ -546,6 +546,12 @@ test "parse unsigned comptime" {
     }
 }
 
+// Dummy field because of https://github.com/zig-lang/zig/issues/557.
+// At top level because of https://github.com/zig-lang/zig/issues/675.
+const Struct = struct {
+    unused: u8,
+};
+
 test "fmt.format" {
     {
         var buf1: [32]u8 = undefined;
@@ -577,6 +583,14 @@ test "fmt.format" {
         const result = try bufPrint(buf1[0..], "u3: {}\n", value);
         assert(mem.eql(u8, result, "u3: 5\n"));
     }
+    {
+        var buf1: [32]u8 = undefined;
+        const value = Struct {
+            .unused = 42,
+        };
+        const result = try bufPrint(buf1[0..], "pointer: {}\n", &value);
+        assert(mem.startsWith(u8, result, "pointer: Struct@"));
+    }
 
     // TODO get these tests passing in release modes
     // https://github.com/zig-lang/zig/issues/564