Add some type annotations and fix lints

Some things, like `method[...](...)` or `x: ... = ...` python 3.5
doesn't support, so I made a comment instead with the intention that it
can someday be made into a real annotation.

1 files changed, 2 insertions, 2 deletions

diff --git a/mesonbuild/envconfig.py b/mesonbuild/envconfig.py
index f4c371f..977d930 100644
--- a/mesonbuild/envconfig.py
+++ b/mesonbuild/envconfig.py
@@ -255,7 +255,7 @@ class MachineInfo:
     def libdir_layout_is_win(self) -> bool:
         return self.is_windows() or self.is_cygwin()
 
-class PerMachineDefaultable(PerMachine[_T]):
+class PerMachineDefaultable(PerMachine[typing.Optional[_T]]):
     """Extends `PerMachine` with the ability to default from `None`s.
     """
     def __init__(self) -> None:
@@ -285,7 +285,7 @@ class PerMachineDefaultable(PerMachine[_T]):
         if self.host == self.build:
             self.host = None
 
-class MachineInfos(PerMachineDefaultable[typing.Optional[MachineInfo]]):
+class MachineInfos(PerMachineDefaultable[MachineInfo]):
     def matches_build_machine(self, machine: MachineChoice) -> bool:
         return self.build == self[machine]