File: constexpr-duffs-device.cpp

package info (click to toggle)
llvm-toolchain-9 1%3A9.0.1-16.1
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 882,388 kB
  • sloc: cpp: 4,167,636; ansic: 714,256; asm: 457,610; python: 155,927; objc: 65,094; sh: 42,856; lisp: 26,908; perl: 7,786; pascal: 7,722; makefile: 6,881; ml: 5,581; awk: 3,648; cs: 2,027; xml: 888; javascript: 381; ruby: 156
file content (32 lines) | stat: -rw-r--r-- 942 bytes parent folder | download | duplicates (28)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
// RUN: %clang_cc1 -std=c++1y -verify %s

// expected-no-diagnostics
constexpr void copy(const char *from, unsigned long count, char *to) {
        unsigned long n = (count + 7) / 8;
        switch(count % 8) {
        case 0: do {    *to++ = *from++;
        case 7:         *to++ = *from++;
        case 6:         *to++ = *from++;
        case 5:         *to++ = *from++;
        case 4:         *to++ = *from++;
        case 3:         *to++ = *from++;
        case 2:         *to++ = *from++;
        case 1:         *to++ = *from++;
                } while(--n > 0);
        }
}

struct S {
  char stuff[14];
  constexpr S() : stuff{} {
    copy("Hello, world!", 14, stuff);
  }
};

constexpr bool streq(const char *a, const char *b) {
  while (*a && *a == *b) ++a, ++b;
  return *a == *b;
}

static_assert(streq(S().stuff, "Hello, world!"), "should be same");
static_assert(!streq(S().stuff, "Something else"), "should be different");