arrayTypeAssumeCapacity

fn arrayTypeAssumeCapacity(self: *Builder, len: u64, child: Type) Type {
    if (std.math.cast(u32, len)) |small_len| {
        const Adapter = struct {
            builder: *const Builder,
            pub fn hash(_: @This(), key: Type.Vector) u32 {
                return @truncate(std.hash.Wyhash.hash(
                    comptime std.hash.int(@backingInt(Type.Tag.small_array)),
                    std.mem.asBytes(&key),
                ));
            }
            pub fn eql(ctx: @This(), lhs_key: Type.Vector, _: void, rhs_index: usize) bool {
                const rhs_data = ctx.builder.type_items.items[rhs_index];
                return rhs_data.tag == .small_array and
                    std.meta.eql(lhs_key, ctx.builder.typeExtraData(Type.Vector, rhs_data.data));
            }
        };
        const data = Type.Vector{ .len = small_len, .child = child };
        const gop = self.type_map.getOrPutAssumeCapacityAdapted(data, Adapter{ .builder = self });
        if (!gop.found_existing) {
            gop.key_ptr.* = {};
            gop.value_ptr.* = {};
            self.type_items.appendAssumeCapacity(.{
                .tag = .small_array,
                .data = self.addTypeExtraAssumeCapacity(data),
            });
        }
        return @fromBackingInt(@intCast(gop.index));
    } else {
        const Adapter = struct {
            builder: *const Builder,
            pub fn hash(_: @This(), key: Type.Array) u32 {
                return @truncate(std.hash.Wyhash.hash(
                    comptime std.hash.int(@backingInt(Type.Tag.array)),
                    std.mem.asBytes(&key),
                ));
            }
            pub fn eql(ctx: @This(), lhs_key: Type.Array, _: void, rhs_index: usize) bool {
                const rhs_data = ctx.builder.type_items.items[rhs_index];
                return rhs_data.tag == .array and
                    std.meta.eql(lhs_key, ctx.builder.typeExtraData(Type.Array, rhs_data.data));
            }
        };
        const data = Type.Array{
            .len_lo = @truncate(len),
            .len_hi = @intCast(len >> 32),
            .child = child,
        };
        const gop = self.type_map.getOrPutAssumeCapacityAdapted(data, Adapter{ .builder = self });
        if (!gop.found_existing) {
            gop.key_ptr.* = {};
            gop.value_ptr.* = {};
            self.type_items.appendAssumeCapacity(.{
                .tag = .array,
                .data = self.addTypeExtraAssumeCapacity(data),
            });
        }
        return @fromBackingInt(@intCast(gop.index));
    }
}