C++ aggregate

Table of contents

An aggregate is an array or a class with

• no user-declared or inherited constructors,
• no private or protected direct non-static data members,
• no virtual functions, and
• no virtual, private, or protected base classes.

Aggregates can be initialized in aggregate initialization, and, for most cases, decomposed in a structured binding:

struct Point {
  int x, y;
}; // aggregate

int main( [[maybe_unused]] int argc, [[maybe_unused]] char **argv )
{
  Point pt           = {1, 2}; // aggregate init
  auto const &[x, y] = pt;     // decomposition

  cout << "x: " << x << " y: " << y << endl;
  return 0;
}

Possible output

x: 1 y: 2

References

• Reflection for aggregates