OS: Ubuntu 16.04 LTS
VSCode ver: 1.20.0
C/C++ Ext ver: 0.14.6

1. Enter the following code into an editor and save.

#include <memory>

namespace b
{
    class Base
    {
    };
}

namespace d
{
    class Derived : public b::Base
    {
    };
}

int main( void )
{
    auto p = std::make_unique< d::Derived >();

    std::unique_ptr< b::Base > q = std::move( p );

    return 0;
}

VSCode incorrectly reports the error:

no suitable user-defined conversion from "std::unique_ptr<d::Derived, std::default_delete<d::Derived>>" to "std::unique_ptr<b::Base, std::default_delete<b::Base>>" exists

Whereas without the namespaces VSCode correctly reports no error.

#include <memory>

class Base
{
};

class Derived : public Base
{
};

int main( void )
{
    auto p = std::make_unique< Derived >();

    std::unique_ptr< Base > q = std::move( p );

    return 0;
}