std::is_trivial is a UnaryTypeTrait.

If T is a trivial type, provides the member constant value equal to true. For any other type, value is false.

If std::remove_all_extents_t<T> is an incomplete type and not (possibly cv-qualified) void, the behavior is undefined.

If the program adds specializations for std::is_trivial or std::is_trivial_v, the behavior is undefined.

Template parameters

Helper variable template

Example

#include <type_traits>

struct A { int m; };
static_assert(std::is_trivial_v<A> == true);

struct B { B() {} };
static_assert(std::is_trivial_v<B> == false);

// The following class shows why std::is_trivial(_v) may be a pitfall.
class C
{
private:
    C() = default;
};

static_assert(std::is_trivial_v<C> == true);
static_assert(std::is_trivially_default_constructible_v<C> == false);

int main() {}

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

See also