zig

commit 87b10400c2a2d39f33e361cf4d7fd8caee7e519b (tree)
parent 3d780cf2ef8391b6b48124f599858ee99ddc4cdc
Author: Raul Leal <raulgrell@gmail.com>
Date:   Wed, 22 Aug 2018 18:12:08 +0100

allow implicit cast from *[N]T to ?[*]T (#1398)

* allow implicit cast from *[N]T to ?[*]T


Diffstat:
M
src/ir.cpp
 | 
13
+++++++++++++
M
test/cases/cast.zig
 | 
12
++++++++++++

2 files changed, 25 insertions(+), 0 deletions(-)
diff --git a/src/ir.cpp b/src/ir.cpp
@@ -10697,6 +10697,19 @@ static IrInstruction *ir_analyze_cast(IrAnalyze *ira, IrInstruction *source_inst
                 return ira->codegen->invalid_instruction;
 
             return cast2;
+        } else if (
+            wanted_child_type->id == TypeTableEntryIdPointer &&
+            wanted_child_type->data.pointer.ptr_len == PtrLenUnknown &&
+            actual_type->id == TypeTableEntryIdPointer &&
+            actual_type->data.pointer.ptr_len == PtrLenSingle &&
+            actual_type->data.pointer.child_type->id == TypeTableEntryIdArray &&
+            actual_type->data.pointer.alignment >= wanted_child_type->data.pointer.alignment &&
+            types_match_const_cast_only(ira, wanted_child_type->data.pointer.child_type,
+            actual_type->data.pointer.child_type->data.array.child_type, source_node,
+            !wanted_child_type->data.pointer.is_const).id == ConstCastResultIdOk)
+        {
+            IrInstruction *cast1 = ir_resolve_ptr_of_array_to_slice(ira, source_instr, value, wanted_child_type);
+            return ir_analyze_maybe_wrap(ira, source_instr, cast1, wanted_type);
         }
     }
 
diff --git a/test/cases/cast.zig b/test/cases/cast.zig
@@ -485,3 +485,14 @@ fn MakeType(comptime T: type) type {
         }
     };
 }
+
+test "implicit cast from *[N]T to ?[*]T" {
+  var x: ?[*]u16 = null;
+  var y: [4]u16 = [4]u16 {0, 1, 2, 3};
+
+  x = &y;
+  assert(std.mem.eql(u16, x.?[0..4], y[0..4]));
+  x.?[0] = 8;
+  y[3] = 6;
+  assert(std.mem.eql(u16, x.?[0..4], y[0..4]));
+}
+\ No newline at end of file