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#include <cstdio>
#include <string>
#include <vector>
// If we have libc++ 4.0 or greater we should have <variant>
// According to libc++ C++1z status page https://libcxx.llvm.org/cxx1z_status.html
#if _LIBCPP_VERSION >= 4000
#include <variant>
#define HAVE_VARIANT 1
#else
#define HAVE_VARIANT 0
#endif
struct S {
operator int() { throw 42; }
} ;
int main()
{
bool has_variant = HAVE_VARIANT ;
printf( "%d\n", has_variant ) ; // break here
#if HAVE_VARIANT == 1
std::variant<int, double, char> v1;
std::variant<int, double, char> &v1_ref = v1;
std::variant<int, double, char> v2;
std::variant<int, double, char> v3;
std::variant<std::variant<int,double,char>> v_v1 ;
std::variant<int, double, char> v_no_value;
// The next variant has 300 types, meaning the type index does not fit in
// a byte and must be `unsigned short` instead of `unsigned char` when
// using the unstable libc++ ABI. With stable libc++ ABI, the type index
// is always just `unsigned int`.
std::variant<
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int, int, int, int, int, int, int, int, int,
int, int, int, int, int, int>
v_300_types_no_value;
v1 = 12; // v contains int
v_v1 = v1 ;
int i = std::get<int>(v1);
printf( "%d\n", i ); // break here
v2 = 2.0 ;
double d = std::get<double>(v2) ;
printf( "%f\n", d );
v3 = 'A' ;
char c = std::get<char>(v3) ;
printf( "%d\n", c );
// Checking v1 above and here to make sure we done maintain the incorrect
// state when we change its value.
v1 = 2.0;
d = std::get<double>(v1) ;
printf( "%f\n", d ); // break here
try {
v_no_value.emplace<0>(S());
} catch( ... ) {}
printf( "%zu\n", v_no_value.index() ) ;
try {
v_300_types_no_value.emplace<0>(S());
} catch (...) {
}
printf("%zu\n", v_300_types_no_value.index());
#endif
return 0; // break here
}
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