From 647901b4a82dbb89656c620d4d4a89869fdf1fa0 Mon Sep 17 00:00:00 2001
From: Tadeo Kondrak <me@tadeo.ca>
Date: Thu, 30 Apr 2020 04:30:01 -0600
Subject: [PATCH] Constify TypeInfo

---
 lib/std/builtin.zig | 18 +++++++++---------
 lib/std/meta.zig    | 12 ++++++------
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/lib/std/builtin.zig b/lib/std/builtin.zig
index 9d419f9af..9b0293228 100644
--- a/lib/std/builtin.zig
+++ b/lib/std/builtin.zig
@@ -235,8 +235,8 @@ pub const TypeInfo = union(enum) {
     /// therefore must be kept in sync with the compiler implementation.
     pub const Struct = struct {
         layout: ContainerLayout,
-        fields: []StructField,
-        decls: []Declaration,
+        fields: []const StructField,
+        decls: []const Declaration,
     };
 
     /// This data structure is used by the Zig language code generation and
@@ -261,7 +261,7 @@ pub const TypeInfo = union(enum) {
 
     /// This data structure is used by the Zig language code generation and
     /// therefore must be kept in sync with the compiler implementation.
-    pub const ErrorSet = ?[]Error;
+    pub const ErrorSet = ?[]const Error;
 
     /// This data structure is used by the Zig language code generation and
     /// therefore must be kept in sync with the compiler implementation.
@@ -275,8 +275,8 @@ pub const TypeInfo = union(enum) {
     pub const Enum = struct {
         layout: ContainerLayout,
         tag_type: type,
-        fields: []EnumField,
-        decls: []Declaration,
+        fields: []const EnumField,
+        decls: []const Declaration,
         is_exhaustive: bool,
     };
 
@@ -293,8 +293,8 @@ pub const TypeInfo = union(enum) {
     pub const Union = struct {
         layout: ContainerLayout,
         tag_type: ?type,
-        fields: []UnionField,
-        decls: []Declaration,
+        fields: []const UnionField,
+        decls: []const Declaration,
     };
 
     /// This data structure is used by the Zig language code generation and
@@ -312,7 +312,7 @@ pub const TypeInfo = union(enum) {
         is_generic: bool,
         is_var_args: bool,
         return_type: ?type,
-        args: []FnArg,
+        args: []const FnArg,
     };
 
     /// This data structure is used by the Zig language code generation and
@@ -358,7 +358,7 @@ pub const TypeInfo = union(enum) {
                 is_export: bool,
                 lib_name: ?[]const u8,
                 return_type: type,
-                arg_names: [][]const u8,
+                arg_names: []const []const u8,
 
                 /// This data structure is used by the Zig language code generation and
                 /// therefore must be kept in sync with the compiler implementation.
diff --git a/lib/std/meta.zig b/lib/std/meta.zig
index e38712af2..4fc74282a 100644
--- a/lib/std/meta.zig
+++ b/lib/std/meta.zig
@@ -219,7 +219,7 @@ test "std.meta.containerLayout" {
     testing.expect(containerLayout(U3) == .Extern);
 }
 
-pub fn declarations(comptime T: type) []TypeInfo.Declaration {
+pub fn declarations(comptime T: type) []const TypeInfo.Declaration {
     return switch (@typeInfo(T)) {
         .Struct => |info| info.decls,
         .Enum => |info| info.decls,
@@ -243,7 +243,7 @@ test "std.meta.declarations" {
         fn a() void {}
     };
 
-    const decls = comptime [_][]TypeInfo.Declaration{
+    const decls = comptime [_][]const TypeInfo.Declaration{
         declarations(E1),
         declarations(S1),
         declarations(U1),
@@ -292,10 +292,10 @@ test "std.meta.declarationInfo" {
 }
 
 pub fn fields(comptime T: type) switch (@typeInfo(T)) {
-    .Struct => []TypeInfo.StructField,
-    .Union => []TypeInfo.UnionField,
-    .ErrorSet => []TypeInfo.Error,
-    .Enum => []TypeInfo.EnumField,
+    .Struct => []const TypeInfo.StructField,
+    .Union => []const TypeInfo.UnionField,
+    .ErrorSet => []const TypeInfo.Error,
+    .Enum => []const TypeInfo.EnumField,
     else => @compileError("Expected struct, union, error set or enum type, found '" ++ @typeName(T) ++ "'"),
 } {
     return switch (@typeInfo(T)) {