rs_bindings_from_cc/test/struct/inheritance/upcast.h

// Part of the Crubit project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

#ifndef CRUBIT_RS_BINDINGS_FROM_CC_TEST_STRUCT_INHERITANCE_UPCAST_H_
#define CRUBIT_RS_BINDINGS_FROM_CC_TEST_STRUCT_INHERITANCE_UPCAST_H_
#include <stddef.h>

#pragma clang lifetime_elision

class Base0 {};

class Base1 {
  int base1_field_ = 1;  // NOLINT(clang-diagnostic-unused-private-field)
};
class Base2 {
  char base2_field_ = 2;  // NOLINT(clang-diagnostic-unused-private-field)
};
class Base3 {
  char base3_field_ = 3;  // NOLINT(clang-diagnostic-unused-private-field)
};

class Base4 : public Base2, public Base3 {
  char base4_field_ = 4;  // NOLINT(clang-diagnostic-unused-private-field)
};

struct Derived final : Base0, Base1, Base4 {
  char derived_field = 5;

  size_t base0_address() const {
    const Base0* base = this;
    return reinterpret_cast<size_t>(base);
  }

  size_t base1_address() const {
    const Base1* base = this;
    return reinterpret_cast<size_t>(base);
  }

  size_t base2_address() const {
    const Base2* base = this;
    return reinterpret_cast<size_t>(base);
  }

  size_t base3_address() const {
    const Base3* base = this;
    return reinterpret_cast<size_t>(base);
  }

  size_t base4_address() const {
    const Base4* base = this;
    return reinterpret_cast<size_t>(base);
  }

 private:
  char private_field;  // NOLINT(clang-diagnostic-unused-private-field)
};

namespace virtual_inheritance {

class VirtualBase2 : public virtual Base1 {};
class VirtualBase3 : public virtual Base1 {};

class VirtualDerived : public virtual VirtualBase2,
                       public virtual VirtualBase3 {
 public:
  size_t base1_address() const {
    const Base1* base = this;
    return reinterpret_cast<size_t>(base);
  }

  size_t base2_address() const {
    const VirtualBase2* base = this;
    return reinterpret_cast<size_t>(base);
  }

  size_t base3_address() const {
    const VirtualBase3* base = this;
    return reinterpret_cast<size_t>(base);
  }
};

}  // namespace virtual_inheritance

namespace another_namespace {

// This class has the same name as another `VirtualBase2` above (in another
// namespace) to check that upcast thunks have unique names that take the
// namespace into account.
class VirtualBase2 : public virtual Base1 {
 public:
  VirtualBase2() = default;

  size_t base1_address() const {
    const Base1* base = this;
    return reinterpret_cast<size_t>(base);
  }
};

}  // namespace another_namespace

#endif  // CRUBIT_RS_BINDINGS_FROM_CC_TEST_STRUCT_INHERITANCE_UPCAST_H_