fuchsia-multiple-inheritance

Warns if a class inherits from multiple classes that are not pure virtual.

For example, declaring a class that inherits from multiple concrete classes is disallowed:

class Base_A {
public:
  virtual int foo() { return 0; }
};

class Base_B {
public:
  virtual int bar() { return 0; }
};

// Warning
class Bad_Child1 : public Base_A, Base_B {};

A class that inherits from a pure virtual is allowed:

class Interface_A {
public:
  virtual int foo() = 0;
};

class Interface_B {
public:
  virtual int bar() = 0;
};

// No warning
class Good_Child1 : public Interface_A, Interface_B {
  virtual int foo() override { return 0; }
  virtual int bar() override { return 0; }
};

See the features disallowed in Fuchsia at https://fuchsia.googlesource.com/zircon/+/master/docs/cxx.md