cppyy fails to find template type with template type as final parameter

[tristanpye]

If the final parameter of a templated typedef is a template type, then cppyy fails to find the type (unless the template type is the only parameter).

import cppyy

cppyy.cppdef('''
template<class T>
class F;

template<class T>
class V;

using i = F<void (int)>;
using v = F<void (V<int>)>;

using ii = F<void (int,int)>;
using iv = F<void (int,V<int>)>;  
using vi = F<void (V<int>,int)>;  
using vv = F<void (V<int>,V<int>)>;  

using iii = F<void (int,int,int)>;  
using ivi = F<void (int,V<int>,int)>;  
using vii = F<void (V<int>,int,int)>;  
using vvi = F<void (V<int>,V<int>,int)>;  

using iiv = F<void (int,int,V<int>)>;  
using ivv = F<void (int,V<int>,V<int>)>;  
using viv = F<void (V<int>,int,V<int>)>;  
using vvv = F<void (V<int>,V<int>,V<int>)>;  

''')

if __name__ == '__main__':
    for t in ['i','v',
              'ii', 'iv', 'vi', 'vv',
              'iii', 'ivi', 'vii', 'vvi',
              'iiv', 'ivv', 'viv', 'vvv']:
        try:
            cpp = getattr(cppyy.gbl,t)
            print(f'{t:5} ok')
        except AttributeError as e:
            print(f'{t:5} not found')

results in

i     ok
v     ok
ii    ok
iv    not found
vi    ok
vv    not found
iii   ok
ivi   ok
vii   ok
vvi   ok
iiv   not found
ivv   not found
viv   not found
vvv   not found

Real-world use of this was using std::function for F and std::vector for V, and various different types instead of int.

[wlav]

Thanks for the nice reproducer!

Looks like a name parsing error in upstream (in all cases, the decl is actually found, but when constructing the internal names, they are each missing a ), leading to invalidation on the cppyy side). Will take some digging.

[wlav]

Fixed in repo (cppyy-backend).

[wlav]

Fix released with 2.3.0 and its dependencies.