typing: simplify type annotations for libraries

In a bunch of places we need to list various types of libraries
including custom_target outputs, and it gets very long. Use a common
T.Union for this.

1 files changed, 2 insertions, 1 deletions

diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index 98e3c93..c626ce5 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -57,6 +57,7 @@ if T.TYPE_CHECKING:
     from .mparser import BaseNode
 
     GeneratedTypes = T.Union['CustomTarget', 'CustomTargetIndex', 'GeneratedList']
+    LibTypes = T.Union['SharedLibrary', 'StaticLibrary', 'CustomTarget', 'CustomTargetIndex']
 
 pch_kwargs = {'c_pch', 'cpp_pch'}
 
@@ -755,7 +756,7 @@ class BuildTarget(Target):
         self.external_deps: T.List[dependencies.Dependency] = []
         self.include_dirs: T.List['IncludeDirs'] = []
         self.link_language = kwargs.get('link_language')
-        self.link_targets: T.List[T.Union[SharedLibrary, StaticLibrary, 'CustomTarget', 'CustomTargetIndex']] = []
+        self.link_targets: T.List[LibTypes] = []
         self.link_whole_targets: T.List[T.Union[StaticLibrary, CustomTarget, CustomTargetIndex]] = []
         self.link_depends = []
         self.added_deps = set()