CppCompileErrorMyPolicyMyMethodIsNotAdirectBaseClassOfMyClassMyPolicy.md

 

 

 

 

 

(C++) 'MyPolicy::MyMethod' is not a direct base class of 'MyClass<MyPolicy>'

 

Compile error.

 

Full error message

 

---

[C++ Error] UnitMain.cpp(4): E2507 'MyPolicy::MyMethod' is not a direct base class of 'MyClass<MyPolicy>'

 

 

 

 

 

Cause

 

IDE: C++ Builder 6.0

Compiler: Borland BCC32.EXE version 6.0.10.157

 

---

template <typename MyPolicy> struct MyClass : public MyPolicy {   using MyPolicy::MyMethod; };

 

This example is simplified from the example at the WikiPedia page about policy-based design.

 

The same code does compile using the IDE Dev-C++ version 4.9.9.2 its default compiler.

 

 

 

 

 

Solution

 

By removing the using statement, it will work.

 

---

template <typename MyPolicy> struct MyClass : public MyPolicy { };

 

Policies requires a compiler with highly robust support for templates [1].

 

 

 

 

 

References

 

1. The WikiPedia page about policy-based design