Support multiple custom string conversions.

Cython/Compiler/PyrexTypes.py

@@ -3057,6 +3057,7 @@ class CppClassType(CType):
                          X[ix], X[ix], T.from_py_function, except_clause))
             if self.cname in cpp_string_conversions:
                 cls = 'string'
+                tags = self.cname.replace(':', '_'),
             else:
                 cls = self.cname[5:]
             cname = '__pyx_convert_%s_from_py_%s' % (cls, '____'.join(tags))
@@ -3090,6 +3091,7 @@ class CppClassType(CType):
                          X[ix], T.to_py_function, X[ix]))
             if self.cname in cpp_string_conversions:
                 cls = 'string'
+                tags = self.cname.replace(':', '_'),
             else:
                 cls = self.cname[5:]
             cname = "__pyx_convert_%s_to_py_%s" % (cls, "____".join(tags))

tests/run/cpp_custom_string.srctree

@@ -7,7 +7,7 @@ PYTHON -c "import a; a.test_convert()"
 
 from Cython.Build.Dependencies import cythonize
 from Cython.Compiler import PyrexTypes
-PyrexTypes.cpp_string_conversions += ("MyString",)
+PyrexTypes.cpp_string_conversions += ("MyString", "MyString2")
 
 from distutils.core import setup
 
@@ -29,6 +29,12 @@ class MyString {
     std::string value_;
 };
 
+class MyString2 : public MyString {
+  public:
+    MyString2() : MyString() { }
+    MyString2(const char* data, size_t size) : MyString(data, size) { }
+};
+
 ######## a.pyx ########
 
 # distutils: language = c++
@@ -37,9 +43,19 @@ cdef extern from "my_string.cpp":
   cdef cppclass MyString:
     pass
 
+cdef extern from "my_string.cpp":
+  cdef cppclass MyString2:
+    pass
+
 def do_convert(MyString value):
     return value
 
+def do_convert2(MyString2 value):
+    return value
+
 def test_convert():
     assert do_convert(b"abc") == b"abc"
     assert do_convert(b"ab\0c") == b"ab\0c"
+
+    assert do_convert2(b"abc") == b"abc"
+    assert do_convert2(b"ab\0c") == b"ab\0c"