1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9// UNSUPPORTED: c++03, c++11, c++14, c++17
10
11// <compare>
12
13// Ensure we reject all cases where an argument other than a literal 0 is used
14// for a comparison against a comparison category type.
15
16// Also ensure that we don't warn about providing a null pointer constant when
17// comparing an ordering type against literal 0, since one of the common
18// implementation strategies is to use a pointer as the "unspecified type".
19// ADDITIONAL_COMPILE_FLAGS: -Wzero-as-null-pointer-constant
20
21#include <compare>
22
23#include "test_macros.h"
24
25#define TEST_FAIL(v, op) \
26 do { \
27 /* invalid types */ \
28 void(v op 0L); \
29 void(0L op v); \
30 void(v op 0.0); \
31 void(0.0 op v); \
32 void(v op nullptr); \
33 void(nullptr op v); \
34 /* invalid value */ \
35 void(v op 1); \
36 void(1 op v); \
37 /* value not known at compile-time */ \
38 int i = 0; \
39 void(v op i); \
40 void(i op v); \
41 } while (false)
42
43#define TEST_PASS(v, op) \
44 do { \
45 void(v op 0); \
46 void(0 op v); \
47 LIBCPP_ONLY(void(v op(1 - 1))); \
48 LIBCPP_ONLY(void((1 - 1) op v)); \
49 } while (false)
50
51template <typename T>
52void test_category(T v) {
53 TEST_FAIL(v, ==); // expected-error 30 {{invalid operands to binary expression}}
54 TEST_FAIL(v, !=); // expected-error 30 {{invalid operands to binary expression}}
55 TEST_FAIL(v, <); // expected-error 30 {{invalid operands to binary expression}}
56 TEST_FAIL(v, <=); // expected-error 30 {{invalid operands to binary expression}}
57 TEST_FAIL(v, >); // expected-error 30 {{invalid operands to binary expression}}
58 TEST_FAIL(v, >=); // expected-error 30 {{invalid operands to binary expression}}
59 TEST_FAIL(v, <=>); // expected-error 30 {{invalid operands to binary expression}}
60
61 TEST_PASS(v, ==);
62 TEST_PASS(v, !=);
63 TEST_PASS(v, <);
64 TEST_PASS(v, >);
65 TEST_PASS(v, <=);
66 TEST_PASS(v, >=);
67 TEST_PASS(v, <=>);
68}
69
70void f() {
71 test_category(std::strong_ordering::equivalent);
72 test_category(std::weak_ordering::equivalent);
73 test_category(std::partial_ordering::equivalent);
74}
75

source code of libcxx/test/std/language.support/cmp/cmp.categories.pre/reject-other-than-literal-zero.verify.cpp