Viewing file:  constexpr-neg1.C (1.97 KB) -rw-r--r--
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// Negative examples from N3092 (FCD)
// { dg-do compile { target c++11 } }
// OK: declaration
constexpr int square(int x); // { dg-message "never defined" }
// error: pixel is a type
constexpr struct pixel { // { dg-error ".constexpr." }
int x;
int y;
// OK: declaration
constexpr pixel(int);
};
constexpr pixel::pixel(int a)
// OK: definition
: x(square(a)), y(square(a)) // { dg-error "square" }
{ }
// error: square not defined, so small(2) not constant (5.19), so constexpr
// not satisfied
constexpr pixel small(2); // { dg-message "in .constexpr. expansion of " }
// error: not for parameters
int next(constexpr int x) { // { dg-error "parameter" }
return x + 1;
}
// error: not a definition
extern constexpr int memsz; // { dg-error "definition" }
// error: return type is void
constexpr void f(int x) // { dg-error "void" "" { target c++11_only } }
{ /* ... */ }
// error: use of decrement
constexpr int prev(int x)
{ return --x; } // { dg-error "-- x" "" { target c++11_only } }
// error: body not just return expr
constexpr int g(int x, int n) {
int r = 1;
while (--n > 0) r *= x;
return r;
} // { dg-error "body of .constexpr. function" "" { target c++11_only } }
class debug_flag {
public:
explicit debug_flag(bool);
constexpr bool is_on(); // { dg-error "not a literal type" "" { target c++11_only } } debug_flag not literal type
private:
bool flag;
};
// OK
constexpr int bar(int x, int y) // { dg-message "previously defined here" }
{ return x + y + x*y; }
// ...
// error: redefinition of bar
int bar(int x, int y) // { dg-error "redefinition" }
{ return x * 2 + 3 * y; }
struct pixel2 { // { dg-message "no user-provided default constructor" }
int x, y;
};
constexpr pixel2 ur = { 1294, 1024 };// OK
constexpr pixel2 origin; // { dg-error "uninitialized 'const" }
constexpr const int* addr(const int& ir) { return &ir; } // OK
// error, initializer for constexpr variable not a constant
extern constexpr const int* tp = addr(5); // { dg-error "" }
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