Merge pull request #87 from justinboswell/ctad

Added support for template deduction guides

cxxheaderparser/parser.py

@@ -25,6 +25,7 @@ from .types import (
     Concept,
     DecltypeSpecifier,
     DecoratedType,
+    DeductionGuide,
     EnumDecl,
     Enumerator,
     Field,
@@ -992,7 +993,9 @@ class CxxParser:
 
         self.visitor.on_using_namespace(state, names)
 
-    def _parse_using_declaration(self, tok: LexToken) -> None:
+    def _parse_using_declaration(
+        self, tok: LexToken, doxygen: typing.Optional[str]
+    ) -> None:
         """
         using_declaration: "using" ["typename"] ["::"] nested_name_specifier unqualified_id ";"
                          | "using" "::" unqualified_id ";"
@@ -1004,12 +1007,15 @@ class CxxParser:
         typename, _ = self._parse_pqname(
             tok, fn_ok=True, compound_ok=True, fund_ok=True
         )
-        decl = UsingDecl(typename, self._current_access)
+        decl = UsingDecl(typename, self._current_access, doxygen)
 
         self.visitor.on_using_declaration(self.state, decl)
 
     def _parse_using_typealias(
-        self, id_tok: LexToken, template: typing.Optional[TemplateDecl]
+        self,
+        id_tok: LexToken,
+        template: typing.Optional[TemplateDecl],
+        doxygen: typing.Optional[str],
     ) -> None:
         """
         alias_declaration: "using" IDENTIFIER "=" type_id ";"
@@ -1023,7 +1029,7 @@ class CxxParser:
 
         dtype = self._parse_cv_ptr(parsed_type)
 
-        alias = UsingAlias(id_tok.value, dtype, template, self._current_access)
+        alias = UsingAlias(id_tok.value, dtype, template, self._current_access, doxygen)
 
         self.visitor.on_using_alias(self.state, alias)
 
@@ -1052,9 +1058,9 @@ class CxxParser:
                 raise CxxParseError(
                     "unexpected using-declaration when parsing alias-declaration", tok
                 )
-            self._parse_using_declaration(tok)
+            self._parse_using_declaration(tok, doxygen)
         else:
-            self._parse_using_typealias(tok, template)
+            self._parse_using_typealias(tok, template, doxygen)
 
         # All using things end with a semicolon
         self._next_token_must_be(";")
@@ -1863,10 +1869,9 @@ class CxxParser:
     _auto_return_typename = PQName([AutoSpecifier()])
 
     def _parse_trailing_return_type(
-        self, fn: typing.Union[Function, FunctionType]
-    ) -> None:
+        self, return_type: typing.Optional[DecoratedType]
+    ) -> DecoratedType:
         # entry is "->"
-        return_type = fn.return_type
         if not (
             isinstance(return_type, Type)
             and not return_type.const
@@ -1885,8 +1890,7 @@ class CxxParser:
 
         dtype = self._parse_cv_ptr(parsed_type)
 
-        fn.has_trailing_return = True
-        fn.return_type = dtype
+        return dtype
 
     def _parse_fn_end(self, fn: Function) -> None:
         """
@@ -1907,18 +1911,19 @@ class CxxParser:
         else:
             rtok = self.lex.token_if("requires")
             if rtok:
-                fn_template = fn.template
-                if fn_template is None:
+                # requires on a function must always be accompanied by a template
+                if fn.template is None:
                     raise self._parse_error(rtok)
-                elif isinstance(fn_template, list):
-                    fn_template = fn_template[0]
-                fn_template.raw_requires_post = self._parse_requires(rtok)
+                fn.raw_requires = self._parse_requires(rtok)
+
+        if self.lex.token_if("ARROW"):
+            return_type = self._parse_trailing_return_type(fn.return_type)
+            fn.has_trailing_return = True
+            fn.return_type = return_type
 
         if self.lex.token_if("{"):
             self._discard_contents("{", "}")
             fn.has_body = True
-        elif self.lex.token_if("ARROW"):
-            self._parse_trailing_return_type(fn)
 
     def _parse_method_end(self, method: Method) -> None:
         """
@@ -1962,7 +1967,12 @@ class CxxParser:
             elif tok_value in ("&", "&&"):
                 method.ref_qualifier = tok_value
             elif tok_value == "->":
-                self._parse_trailing_return_type(method)
+                return_type = self._parse_trailing_return_type(method.return_type)
+                method.has_trailing_return = True
+                method.return_type = return_type
+                if self.lex.token_if("{"):
+                    self._discard_contents("{", "}")
+                    method.has_body = True
                 break
             elif tok_value == "throw":
                 tok = self._next_token_must_be("(")
@@ -1974,12 +1984,7 @@ class CxxParser:
                     toks = self._consume_balanced_tokens(otok)[1:-1]
                 method.noexcept = self._create_value(toks)
             elif tok_value == "requires":
-                method_template = method.template
-                if method_template is None:
-                    raise self._parse_error(tok)
-                elif isinstance(method_template, list):
-                    method_template = method_template[0]
-                method_template.raw_requires_post = self._parse_requires(tok)
+                method.raw_requires = self._parse_requires(tok)
             else:
                 self.lex.return_token(tok)
                 break
@@ -1998,6 +2003,7 @@ class CxxParser:
         is_friend: bool,
         is_typedef: bool,
         msvc_convention: typing.Optional[LexToken],
+        is_guide: bool = False,
     ) -> bool:
         """
         Assumes the caller has already consumed the return type and name, this consumes the
@@ -2074,7 +2080,21 @@ class CxxParser:
                 self.visitor.on_method_impl(state, method)
 
             return method.has_body or method.has_trailing_return
-
+        elif is_guide:
+            assert isinstance(state, (ExternBlockState, NamespaceBlockState))
+            if not self.lex.token_if("ARROW"):
+                raise self._parse_error(None, expected="Trailing return type")
+            return_type = self._parse_trailing_return_type(
+                Type(PQName([AutoSpecifier()]))
+            )
+            guide = DeductionGuide(
+                return_type,
+                name=pqname,
+                parameters=params,
+                doxygen=doxygen,
+            )
+            self.visitor.on_deduction_guide(state, guide)
+            return False
         else:
             assert return_type is not None
             fn = Function(
@@ -2208,7 +2228,9 @@ class CxxParser:
                 assert not isinstance(dtype, FunctionType)
                 dtype = dtype_fn = FunctionType(dtype, fn_params, vararg)
                 if self.lex.token_if("ARROW"):
-                    self._parse_trailing_return_type(dtype_fn)
+                    return_type = self._parse_trailing_return_type(dtype_fn.return_type)
+                    dtype_fn.has_trailing_return = True
+                    dtype_fn.return_type = return_type
 
             else:
                 msvc_convention = None
@@ -2389,6 +2411,7 @@ class CxxParser:
         destructor = False
         op = None
         msvc_convention = None
+        is_guide = False
 
         # If we have a leading (, that's either an obnoxious grouping
         # paren or it's a constructor
@@ -2439,8 +2462,15 @@ class CxxParser:
                 # grouping paren like "void (name(int x));"
                 toks = self._consume_balanced_tokens(tok)
 
-                # .. not sure what it's grouping, so put it back?
-                self.lex.return_tokens(toks[1:-1])
+                # check to see if the next token is an arrow, and thus a trailing return
+                if self.lex.token_peek_if("ARROW"):
+                    self.lex.return_tokens(toks)
+                    # the leading name of the class/ctor has been parsed as a type before the parens
+                    pqname = parsed_type.typename
+                    is_guide = True
+                else:
+                    # .. not sure what it's grouping, so put it back?
+                    self.lex.return_tokens(toks[1:-1])
 
         if dtype:
             msvc_convention = self.lex.token_if_val(*self._msvc_conventions)
@@ -2471,6 +2501,7 @@ class CxxParser:
                 is_friend,
                 is_typedef,
                 msvc_convention,
+                is_guide,
             )
         elif msvc_convention:
             raise self._parse_error(msvc_convention)

cxxheaderparser/simple.py

@@ -35,6 +35,7 @@ from dataclasses import dataclass, field
 from .types import (
     ClassDecl,
     Concept,
+    DeductionGuide,
     EnumDecl,
     Field,
     ForwardDecl,
@@ -123,6 +124,9 @@ class NamespaceScope:
     #: Child namespaces
     namespaces: typing.Dict[str, "NamespaceScope"] = field(default_factory=dict)
 
+    #: Deduction guides
+    deduction_guides: typing.List[DeductionGuide] = field(default_factory=list)
+
 
 Block = typing.Union[ClassScope, NamespaceScope]
 
@@ -317,6 +321,11 @@ class SimpleCxxVisitor:
     def on_class_end(self, state: SClassBlockState) -> None:
         pass
 
+    def on_deduction_guide(
+        self, state: SNonClassBlockState, guide: DeductionGuide
+    ) -> None:
+        state.user_data.deduction_guides.append(guide)
+
 
 def parse_string(
     content: str,

cxxheaderparser/types.py

@@ -526,9 +526,6 @@ class TemplateDecl:
     #: template <typename T> requires ...
     raw_requires_pre: typing.Optional[Value] = None
 
-    #: template <typename T> int main() requires ...
-    raw_requires_post: typing.Optional[Value] = None
-
 
 #: If no template, this is None. This is a TemplateDecl if this there is a single
 #: declaration:
@@ -730,6 +727,13 @@ class Function:
     #: is the string "conversion" and the full Type is found in return_type
     operator: typing.Optional[str] = None
 
+    #: A requires constraint following the function declaration. If you need the
+    #: prior, look at TemplateDecl.raw_requires_pre. At the moment this is just
+    #: a raw value, if we interpret it in the future this will change.
+    #:
+    #: template <typename T> int main() requires ...
+    raw_requires: typing.Optional[Value] = None
+
 
 @dataclass
 class Method(Function):
@@ -848,6 +852,7 @@ class Field:
     constexpr: bool = False
     mutable: bool = False
     static: bool = False
+    inline: bool = False
 
     doxygen: typing.Optional[str] = None
 
@@ -865,6 +870,9 @@ class UsingDecl:
     #: If within a class, the access level for this decl
     access: typing.Optional[str] = None
 
+    #: Documentation if present
+    doxygen: typing.Optional[str] = None
+
 
 @dataclass
 class UsingAlias:
@@ -885,3 +893,24 @@ class UsingAlias:
 
     #: If within a class, the access level for this decl
     access: typing.Optional[str] = None
+
+    #: Documentation if present
+    doxygen: typing.Optional[str] = None
+
+
+@dataclass
+class DeductionGuide:
+    """
+    .. code-block:: c++
+
+    template <class T>
+    MyClass(T) -> MyClass(int);
+    """
+
+    #: Only constructors and destructors don't have a return type
+    result_type: typing.Optional[DecoratedType]
+
+    name: PQName
+    parameters: typing.List[Parameter]
+
+    doxygen: typing.Optional[str] = None

cxxheaderparser/visitor.py

@@ -9,6 +9,7 @@ else:
 
 from .types import (
     Concept,
+    DeductionGuide,
     EnumDecl,
     Field,
     ForwardDecl,
@@ -236,6 +237,13 @@ class CxxVisitor(Protocol):
         ``on_variable`` for each instance declared.
         """
 
+    def on_deduction_guide(
+        self, state: NonClassBlockState, guide: DeductionGuide
+    ) -> None:
+        """
+        Called when a deduction guide is encountered
+        """
+
 
 class NullVisitor:
     """
@@ -318,5 +326,10 @@ class NullVisitor:
     def on_class_end(self, state: ClassBlockState) -> None:
         return None
 
+    def on_deduction_guide(
+        self, state: NonClassBlockState, guide: DeductionGuide
+    ) -> None:
+        return None
+
 
 null_visitor = NullVisitor()

tests/test_class.py

@@ -3336,3 +3336,40 @@ def test_constructor_outside_class() -> None:
             ]
         )
     )
+
+
+def test_class_inline_static() -> None:
+    content = """
+      struct X {
+          inline static bool Foo = 1;
+      };
+    """
+    data = parse_string(content, cleandoc=True)
+
+    assert data == ParsedData(
+        namespace=NamespaceScope(
+            classes=[
+                ClassScope(
+                    class_decl=ClassDecl(
+                        typename=PQName(
+                            segments=[NameSpecifier(name="X")], classkey="struct"
+                        )
+                    ),
+                    fields=[
+                        Field(
+                            access="public",
+                            type=Type(
+                                typename=PQName(
+                                    segments=[FundamentalSpecifier(name="bool")]
+                                )
+                            ),
+                            name="Foo",
+                            value=Value(tokens=[Token(value="1")]),
+                            static=True,
+                            inline=True,
+                        )
+                    ],
+                )
+            ]
+        )
+    )

tests/test_concepts.py

@@ -6,6 +6,7 @@ from cxxheaderparser.types import (
     Concept,
     Function,
     FundamentalSpecifier,
+    Method,
     MoveReference,
     NameSpecifier,
     PQName,
@@ -495,15 +496,15 @@ def test_requires_last_elem() -> None:
                         )
                     ],
                     template=TemplateDecl(
-                        params=[TemplateTypeParam(typekey="typename", name="T")],
-                        raw_requires_post=Value(
-                            tokens=[
-                                Token(value="Eq"),
-                                Token(value="<"),
-                                Token(value="T"),
-                                Token(value=">"),
-                            ]
-                        ),
+                        params=[TemplateTypeParam(typekey="typename", name="T")]
+                    ),
+                    raw_requires=Value(
+                        tokens=[
+                            Token(value="Eq"),
+                            Token(value="<"),
+                            Token(value="T"),
+                            Token(value=">"),
+                        ]
                     ),
                 )
             ]
@@ -752,14 +753,14 @@ def test_requires_both() -> None:
                                 Token(value=">"),
                             ]
                         ),
-                        raw_requires_post=Value(
-                            tokens=[
-                                Token(value="Subtractable"),
-                                Token(value="<"),
-                                Token(value="T"),
-                                Token(value=">"),
-                            ]
-                        ),
+                    ),
+                    raw_requires=Value(
+                        tokens=[
+                            Token(value="Subtractable"),
+                            Token(value="<"),
+                            Token(value="T"),
+                            Token(value=">"),
+                        ]
                     ),
                 )
             ]
@@ -791,21 +792,87 @@ def test_requires_paren() -> None:
                         )
                     ],
                     template=TemplateDecl(
-                        params=[TemplateTypeParam(typekey="class", name="T")],
-                        raw_requires_post=Value(
-                            tokens=[
-                                Token(value="("),
-                                Token(value="is_purrable"),
-                                Token(value="<"),
-                                Token(value="T"),
-                                Token(value=">"),
-                                Token(value="("),
-                                Token(value=")"),
-                                Token(value=")"),
-                            ]
-                        ),
+                        params=[TemplateTypeParam(typekey="class", name="T")]
+                    ),
+                    raw_requires=Value(
+                        tokens=[
+                            Token(value="("),
+                            Token(value="is_purrable"),
+                            Token(value="<"),
+                            Token(value="T"),
+                            Token(value=">"),
+                            Token(value="("),
+                            Token(value=")"),
+                            Token(value=")"),
+                        ]
                     ),
                 )
             ]
         )
     )
+
+
+def test_non_template_requires() -> None:
+    content = """
+      // clang-format off
+
+      template <class T>
+      struct Payload
+      {
+          constexpr Payload(T v)
+              requires(std::is_pod_v<T>)
+              : Value(v)
+          {
+          }
+      };
+    """
+    data = parse_string(content, cleandoc=True)
+
+    assert data == ParsedData(
+        namespace=NamespaceScope(
+            classes=[
+                ClassScope(
+                    class_decl=ClassDecl(
+                        typename=PQName(
+                            segments=[NameSpecifier(name="Payload")], classkey="struct"
+                        ),
+                        template=TemplateDecl(
+                            params=[TemplateTypeParam(typekey="class", name="T")]
+                        ),
+                    ),
+                    methods=[
+                        Method(
+                            return_type=None,
+                            name=PQName(segments=[NameSpecifier(name="Payload")]),
+                            parameters=[
+                                Parameter(
+                                    type=Type(
+                                        typename=PQName(
+                                            segments=[NameSpecifier(name="T")]
+                                        )
+                                    ),
+                                    name="v",
+                                )
+                            ],
+                            constexpr=True,
+                            has_body=True,
+                            raw_requires=Value(
+                                tokens=[
+                                    Token(value="("),
+                                    Token(value="std"),
+                                    Token(value="::"),
+                                    Token(value="is_pod_v"),
+                                    Token(value="<"),
+                                    Token(value="T"),
+                                    Token(value=">"),
+                                    Token(value=")"),
+                                ]
+                            ),
+                            access="public",
+                            constructor=True,
+                        )
+                    ],
+                )
+            ]
+        )
+    )

tests/test_doxygen.py

@@ -26,6 +26,7 @@ from cxxheaderparser.types import (
     Type,
     Typedef,
     UsingDecl,
+    UsingAlias,
     Value,
     Variable,
 )
@@ -436,3 +437,53 @@ def test_doxygen_attribute() -> None:
             ]
         )
     )
+
+
+def test_doxygen_using_decl() -> None:
+    content = """
+      // clang-format off
+
+      /// Comment
+      using ns::ClassName;
+    """
+    data = parse_string(content, cleandoc=True)
+
+    assert data == ParsedData(
+        namespace=NamespaceScope(
+            using=[
+                UsingDecl(
+                    typename=PQName(
+                        segments=[
+                            NameSpecifier(name="ns"),
+                            NameSpecifier(name="ClassName"),
+                        ]
+                    ),
+                    doxygen="/// Comment",
+                )
+            ]
+        )
+    )
+
+
+def test_doxygen_using_alias() -> None:
+    content = """
+      // clang-format off
+
+      /// Comment
+      using alias = sometype;
+    """
+    data = parse_string(content, cleandoc=True)
+
+    assert data == ParsedData(
+        namespace=NamespaceScope(
+            using_alias=[
+                UsingAlias(
+                    alias="alias",
+                    type=Type(
+                        typename=PQName(segments=[NameSpecifier(name="sometype")])
+                    ),
+                    doxygen="/// Comment",
+                )
+            ]
+        )
+    )

tests/test_fn.py

@@ -1194,3 +1194,67 @@ def test_auto_decltype_return() -> None:
             ]
         )
     )
+
+
+def test_fn_trailing_return_with_body() -> None:
+    content = """
+      auto test() -> void
+      {
+      }
+    """
+    data = parse_string(content, cleandoc=True)
+
+    assert data == ParsedData(
+        namespace=NamespaceScope(
+            functions=[
+                Function(
+                    return_type=Type(
+                        typename=PQName(segments=[FundamentalSpecifier(name="void")])
+                    ),
+                    name=PQName(segments=[NameSpecifier(name="test")]),
+                    parameters=[],
+                    has_body=True,
+                    has_trailing_return=True,
+                )
+            ]
+        )
+    )
+
+
+def test_method_trailing_return_with_body() -> None:
+    content = """
+      struct X {
+          auto test() -> void
+          {
+          }
+      };
+    """
+    data = parse_string(content, cleandoc=True)
+
+    assert data == ParsedData(
+        namespace=NamespaceScope(
+            classes=[
+                ClassScope(
+                    class_decl=ClassDecl(
+                        typename=PQName(
+                            segments=[NameSpecifier(name="X")], classkey="struct"
+                        )
+                    ),
+                    methods=[
+                        Method(
+                            return_type=Type(
+                                typename=PQName(
+                                    segments=[FundamentalSpecifier(name="void")]
+                                )
+                            ),
+                            name=PQName(segments=[NameSpecifier(name="test")]),
+                            parameters=[],
+                            has_body=True,
+                            has_trailing_return=True,
+                            access="public",
+                        )
+                    ],
+                )
+            ]
+        )
+    )

tests/test_template.py

@@ -5,6 +5,7 @@ from cxxheaderparser.types import (
     BaseClass,
     ClassDecl,
     DecltypeSpecifier,
+    DeductionGuide,
     Field,
     ForwardDecl,
     Function,
@@ -2163,3 +2164,86 @@ def test_member_class_template_specialization() -> None:
             ]
         )
     )
+
+
+def test_template_deduction_guide() -> None:
+    content = """
+      template <class CharT, class Traits = std::char_traits<CharT>>
+      Error(std::basic_string_view<CharT, Traits>) -> Error<std::string>;
+    """
+    data = parse_string(content, cleandoc=True)
+
+    assert data == ParsedData(
+        namespace=NamespaceScope(
+            deduction_guides=[
+                DeductionGuide(
+                    result_type=Type(
+                        typename=PQName(
+                            segments=[
+                                NameSpecifier(
+                                    name="Error",
+                                    specialization=TemplateSpecialization(
+                                        args=[
+                                            TemplateArgument(
+                                                arg=Type(
+                                                    typename=PQName(
+                                                        segments=[
+                                                            NameSpecifier(name="std"),
+                                                            NameSpecifier(
+                                                                name="string"
+                                                            ),
+                                                        ]
+                                                    )
+                                                )
+                                            )
+                                        ]
+                                    ),
+                                )
+                            ]
+                        )
+                    ),
+                    name=PQName(segments=[NameSpecifier(name="Error")]),
+                    parameters=[
+                        Parameter(
+                            type=Type(
+                                typename=PQName(
+                                    segments=[
+                                        NameSpecifier(name="std"),
+                                        NameSpecifier(
+                                            name="basic_string_view",
+                                            specialization=TemplateSpecialization(
+                                                args=[
+                                                    TemplateArgument(
+                                                        arg=Type(
+                                                            typename=PQName(
+                                                                segments=[
+                                                                    NameSpecifier(
+                                                                        name="CharT"
+                                                                    )
+                                                                ]
+                                                            )
+                                                        )
+                                                    ),
+                                                    TemplateArgument(
+                                                        arg=Type(
+                                                            typename=PQName(
+                                                                segments=[
+                                                                    NameSpecifier(
+                                                                        name="Traits"
+                                                                    )
+                                                                ]
+                                                            )
+                                                        )
+                                                    ),
+                                                ]
+                                            ),
+                                        ),
+                                    ]
+                                )
+                            )
+                        )
+                    ],
+                )
+            ]
+        )
+    )