gcc/testsuite/g++.dg/ext/char8_t-init-2.C

// Test initialization from UTF-8 literals when -fchar8_t is enabled.
// { dg-do compile }
// { dg-options "-std=c++17 -fchar8_t" }

char c1 = 'x';
char c2 = u8'x';
char8_t c3 = 'x';
char8_t c4 = u8'x';
char8_t c5 = u'x';

const char *pc1 = "x";
const char *pc2 = u8"x"; // { dg-error "invalid conversion from .const char8_t.. to .const char.." "char8_t" }
const char8_t *pc3 = "x"; // { dg-error "invalid conversion from .const char.. to .const char8_t.." "char8_t" }
const char8_t *pc4 = u8"x";
const char8_t *pc5 = u"x"; // { dg-error "cannot convert .const char16_t.. to .const char8_t.. in initialization" "char8_t" }

const char (&rca1)[2] = "x";
const char (&rca2)[2] = u8"x"; // { dg-error "invalid initialization of reference of type .const char ....... from expression of type .const char8_t ...." "char8_t" }
const char8_t (&rca3)[2] = "x"; // { dg-error "invalid initialization of reference of type .const char8_t ....... from expression of type .const char ...." "char8_t" }
const char8_t (&rca4)[2] = u8"x";
const char8_t (&rca5)[2] = u"x"; // { dg-error "invalid initialization of reference of type .const char8_t ....... from expression of type .const char16_t ...." "char8_t" }

char ca1[] = "x";
char ca2[] = u8"x"; // { dg-error "from a string literal with type array of .char8_t." "char8_t" }
char8_t ca3[] = "x"; // { dg-error "from a string literal with type array of .char." "char8_t" }
char8_t ca4[] = u8"x";
char8_t ca5[] = u"x"; // { dg-error "from a string literal with type array of .char16_t." "char8_t" }

signed char sca1[] = "x";
signed char sca2[] = u8"x"; // { dg-error "from a string literal with type array of .char8_t." "char8_t" }

unsigned char uca1[] = "x";
unsigned char uca2[] = u8"x"; // { dg-error "from a string literal with type array of .char8_t." "char8_t" }