Default template argument problem

[Martin]

What's wrong with the following code:

template <typename T = double>
class Base
{};

class Derived : public Base
{};

Compiling it with gcc gives me "expected class name before '{' token".
Saying "public Base<double>" instead of just "public Base" works, of
course, but how come the default template argument is not being used?

 

[Victor Bazarov]

What's wrong with the following code:

template <typename T = double>
class Base
{};

class Derived : public Base
{};

Compiling it with gcc gives me "expected class name before '{' token".
Saying "public Base<double>" instead of just "public Base" works, of
course, but how come the default template argument is not being used?

'Base' is not a class name. It is a template-id, it has to have the
angle brackets. You can leave them empty, but they have to be present:

class Derived : public Base<>
{};

V