Micro-optimization: avoid Bogus[int] types that cause needless boxing (…

…#14354)

I want to get rid of all the bogus types eventually.

mypy/types.py

@@ -153,6 +153,9 @@
 # A placeholder used for Bogus[...] parameters
 _dummy: Final[Any] = object()
 
+# A placeholder for int parameters
+_dummy_int: Final = -999999
+
 
 class TypeOfAny:
  """
@@ -540,8 +543,8 @@ def copy_modified(
  values: Bogus[list[Type]] = _dummy,
  upper_bound: Bogus[Type] = _dummy,
  id: Bogus[TypeVarId | int] = _dummy,
- line: Bogus[int] = _dummy,
- column: Bogus[int] = _dummy,
+ line: int = _dummy_int,
+ column: int = _dummy_int,
  ) -> TypeVarType:
  return TypeVarType(
  self.name,
@@ -550,8 +553,8 @@ def copy_modified(
  self.values if values is _dummy else values,
  self.upper_bound if upper_bound is _dummy else upper_bound,
  self.variance,
- self.line if line is _dummy else line,
- self.column if column is _dummy else column,
+ self.line if line == _dummy_int else line,
+ self.column if column == _dummy_int else column,
  )
 
  def accept(self, visitor: TypeVisitor[T]) -> T:
@@ -658,14 +661,14 @@ def copy_modified(
  self,
  *,
  id: Bogus[TypeVarId | int] = _dummy,
- flavor: Bogus[int] = _dummy,
+ flavor: int = _dummy_int,
  prefix: Bogus[Parameters] = _dummy,
  ) -> ParamSpecType:
  return ParamSpecType(
  self.name,
  self.fullname,
  id if id is not _dummy else self.id,
- flavor if flavor is not _dummy else self.flavor,
+ flavor if flavor != _dummy_int else self.flavor,
  self.upper_bound,
  line=self.line,
  column=self.column,
@@ -1024,10 +1027,10 @@ def accept(self, visitor: TypeVisitor[T]) -> T:
  def copy_modified(
  self,
  # Mark with Bogus because _dummy is just an object (with type Any)
- type_of_any: Bogus[int] = _dummy,
+ type_of_any: int = _dummy_int,
  original_any: Bogus[AnyType | None] = _dummy,
  ) -> AnyType:
- if type_of_any is _dummy:
+ if type_of_any == _dummy_int:
  type_of_any = self.type_of_any
  if original_any is _dummy:
  original_any = self.source_any
@@ -1745,8 +1748,8 @@ def copy_modified(
  name: Bogus[str | None] = _dummy,
  definition: Bogus[SymbolNode] = _dummy,
  variables: Bogus[Sequence[TypeVarLikeType]] = _dummy,
- line: Bogus[int] = _dummy,
- column: Bogus[int] = _dummy,
+ line: int = _dummy_int,
+ column: int = _dummy_int,
  is_ellipsis_args: Bogus[bool] = _dummy,
  implicit: Bogus[bool] = _dummy,
  special_sig: Bogus[str | None] = _dummy,
@@ -1766,8 +1769,8 @@ def copy_modified(
  name=name if name is not _dummy else self.name,
  definition=definition if definition is not _dummy else self.definition,
  variables=variables if variables is not _dummy else self.variables,
- line=line if line is not _dummy else self.line,
- column=column if column is not _dummy else self.column,
+ line=line if line != _dummy_int else self.line,
+ column=column if column != _dummy_int else self.column,
  is_ellipsis_args=(
  is_ellipsis_args if is_ellipsis_args is not _dummy else self.is_ellipsis_args
  ),