xref: /llvm-project/clang/test/SemaCXX/cxx2a-nttp-printing.cpp (revision 6bcef543e3a31da26b0164ba4ed6e79e8f0a72c3)
1 // RUN: %clang_cc1 %s -std=c++20 -fsyntax-only -verify
2 
3 template <int N> struct Str {
StrStr4   constexpr Str(char const (&s)[N]) { __builtin_memcpy(value, s, N); }
5   char value[N];
6 };
7 
8 template <Str V> class ASCII {};
9 
10 void Foo(ASCII<"this nontype template argument is too long to print">); // expected-note {{no known conversion from 'ASCII<Str<43>{"this nontype template argument is too long"}>' to 'ASCII<Str<52>{"this nontype template argument is too long to print"}>'}}
11 void Bar(ASCII<"this nttp argument is too short">);                     // expected-note {{no known conversion from 'ASCII<Str<14>{{119, 97, 105, 116, 32, 97, 32, 115, 27, 99, 111, 110, 100, 0}}>' to 'ASCII<Str<32>{"this nttp argument is too short"}>'}}
12 void Meow(ASCII<"what|">);                                              // expected-note {{no known conversion from 'ASCII<Str<8>{"what??!"}>' to 'ASCII<Str<6>{"what|"}>' for 1st argument}}
13 
test_ascii()14 void test_ascii() {
15   ASCII<"this nontype template argument"
16         " is too long">
17       a;
18   Foo(a);                 // expected-error {{no matching function}}
19   decltype(a)::display(); // expected-error {{no member named 'display' in 'ASCII<Str<43>{"this nontype template argument is [...]"}>'}}
20 }
21 
test_non_ascii()22 void test_non_ascii() {
23   ASCII<"wait a s\033cond"> a;
24   Bar(a);                 // expected-error {{no matching function}}
25   decltype(a)::display(); // expected-error {{no member named 'display' in 'ASCII<Str<14>{{119, 97, 105, 116, 32, 97, 32, 115, 27, 99, ...}}>'}}
26 }
27 
28 // The dialects (C++20 and above) that accept string literals as non-type
29 // template arguments do not support trigraphs.
test_trigraph()30 void test_trigraph() {
31   ASCII<"what??!"> a;     // expected-warning {{trigraph ignored}}
32   Meow(a);                // expected-error {{no matching function}}
33   decltype(a)::display(); // expected-error {{no member named 'display' in 'ASCII<Str<8>{"what??!"}>'}}
34 }
35