remove ability to pass multiple keys to extract_as_list

This makes the typing annotations basically impossible to get right, but
if we only have one key then it's easy. Fortunately python provides
comprehensions, so we don't even need the ability to pass multiple keys,
we can just [extract_as_list(kwargs, c) for c in ('a', 'b', 'c')] and
get the same result.

1 files changed, 1 insertions, 1 deletions

diff --git a/mesonbuild/dependencies/boost.py b/mesonbuild/dependencies/boost.py
index 53a0cfb..b07f3ac 100644
--- a/mesonbuild/dependencies/boost.py
+++ b/mesonbuild/dependencies/boost.py
@@ -272,7 +272,7 @@ class BoostDependency(ExternalDependency):
         self.boost_root = None
 
         # Extract and validate modules
-        self.modules = mesonlib.extract_as_list(kwargs, 'modules')
+        self.modules = mesonlib.extract_as_list(kwargs, 'modules')  # type: T.List[str]
         for i in self.modules:
             if not isinstance(i, str):
                 raise DependencyException('Boost module argument is not a string.')