C++: Ignore explicit template instantiations

Defined in section 14.7.2 of the standard.

Fixes completion for std::string.

The following explicit instantiation appears in bits/basic_string.tcc:
  extern template class basic_string<char>;

This is wrongfully considered a specialization for a forward declaration
(like `template<> class basic_string<char>` is).

Introduce a new Symbol type for explicit instantiations.

Use-case:
template<class T>
struct Foo { T bar; };

template class Foo<int>;

void func()
{
    Foo<int> foo;
    foo.bar; // bar not highlighted
}

Change-Id: I9e35c8c32f6b78fc87b4f4f1fc903b42cfbd2c2b
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/libs/3rdparty/cplusplus/TypeVisitor.h b/src/libs/3rdparty/cplusplus/TypeVisitor.h
index b3a24b1572..86568dcebc 100644
--- a/src/libs/3rdparty/cplusplus/TypeVisitor.h
+++ b/src/libs/3rdparty/cplusplus/TypeVisitor.h
@@ -51,6 +51,7 @@ public:
     virtual void visit(Function *) {}
     virtual void visit(Namespace *) {}
     virtual void visit(Template *) {}
+    virtual void visit(ExplicitInstantiation *) {}
     virtual void visit(Class *) {}
     virtual void visit(Enum *) {}
     virtual void visit(ForwardClassDeclaration *) {}