1 files changed, 59 insertions, 0 deletions

diff --git a/clap/types.zig b/clap/types.zig
new file mode 100644
index 0000000..926659a
--- /dev/null
+++ b/clap/types.zig
@@ -0,0 +1,59 @@
+pub fn isArrayListUnmanaged(comptime T: type) bool {
+    if (@typeInfo(T) != .@"struct" or !@hasDecl(T, "Slice"))
+        return false;
+
+    const ptr_info = switch (@typeInfo(T.Slice)) {
+        .pointer => |info| info,
+        else => return false,
+    };
+
+    return T == std.ArrayListAlignedUnmanaged(ptr_info.child, null) or
+        T == std.ArrayListAlignedUnmanaged(ptr_info.child, ptr_info.alignment);
+}
+
+test isArrayListUnmanaged {
+    try std.testing.expect(!isArrayListUnmanaged(u8));
+    try std.testing.expect(!isArrayListUnmanaged([]const u8));
+    try std.testing.expect(!isArrayListUnmanaged(struct {
+        pub const Slice = []const u8;
+    }));
+    try std.testing.expect(isArrayListUnmanaged(std.ArrayListUnmanaged(u8)));
+}
+
+pub fn allFieldsHaveDefaults(comptime T: type) bool {
+    const info = switch (@typeInfo(T)) {
+        .@"struct" => |s| s,
+        else => return false,
+    };
+
+    inline for (info.fields) |field| {
+        if (field.default_value == null)
+            return false;
+    }
+
+    return true;
+}
+
+test allFieldsHaveDefaults {
+    try std.testing.expect(!allFieldsHaveDefaults(u8));
+    try std.testing.expect(!allFieldsHaveDefaults([]const u8));
+    try std.testing.expect(allFieldsHaveDefaults(struct {}));
+    try std.testing.expect(allFieldsHaveDefaults(struct {
+        a: u8 = 0,
+    }));
+    try std.testing.expect(!allFieldsHaveDefaults(struct {
+        a: u8,
+    }));
+    try std.testing.expect(!allFieldsHaveDefaults(struct {
+        a: u8,
+        b: u8 = 0,
+        c: u8,
+    }));
+    try std.testing.expect(allFieldsHaveDefaults(struct {
+        a: u8 = 1,
+        b: u8 = 0,
+        c: u8 = 3,
+    }));
+}
+
+const std = @import("std");