Function cpp_declaration_template_context 

pub fn cpp_declaration_template_context(
    node: Node<'_>,
    source: &str,
) -> Option<CppTemplateContext>

The template context of the declaration node – a function definition, declaration, field declaration or function declarator, or a class specifier – read from its syntax.

None when the shape is outside what this module models: parser recovery on the path, a local class, a qualified name inside a class body, or more heads than the written owner can consume.