Sema: slice improvements

 * resolve_inferred_alloc now gives a proper mutability attribute to the
   corresponding alloc instruction. Previously, it would fail to mark
   things const.
 * slicing: fix the detection for when the end index equals the length
   of the underlying object. Previously it was using `end - start` but
   it should just use the end index directly. It also takes into account
   when slicing a comptime-known slice.
 * `Type.sentinel`: fix not handling all slice tags

1 files changed, 12 insertions, 0 deletions

diff --git a/test/behavior/slice.zig b/test/behavior/slice.zig
index 0b01139800..d4e8284751 100644
--- a/test/behavior/slice.zig
+++ b/test/behavior/slice.zig
@@ -192,3 +192,15 @@ test "compile time slice of pointer to hard coded address" {
     try expect(@ptrToInt(y) == 0x1400);
     try expect(y.len == 0x400);
 }
+
+test "slice string literal has correct type" {
+    comptime {
+        try expect(@TypeOf("aoeu"[0..]) == *const [4:0]u8);
+        const array = [_]i32{ 1, 2, 3, 4 };
+        try expect(@TypeOf(array[0..]) == *const [4]i32);
+    }
+    var runtime_zero: usize = 0;
+    comptime try expect(@TypeOf("aoeu"[runtime_zero..]) == [:0]const u8);
+    const array = [_]i32{ 1, 2, 3, 4 };
+    comptime try expect(@TypeOf(array[runtime_zero..]) == []const i32);
+}