imports: Switch to Microsoft GSL implementation

... with two minor code base changes compared to previous
use of gsl-lite:

- dag.hpp: ActionNode::Ptr and ArtifactNode::Ptr are not
  wrapped in gsl::not_null<> anymore, due to lack of support
  for wrapping std::unique_ptr<>. More specifically, the
  move constructor is missing, rendering it impossible to
  use std::vector<>::emplace_back().

- utils/cpp/gsl.hpp: New header file added to implement the
  macros ExpectsAudit() and EnsureAudit(), asserts running
  only in debug builds, which were available in gsl-lite but
  are missing in MS GSL.

1 files changed, 3 insertions, 6 deletions

diff --git a/src/buildtool/execution_engine/traverser/traverser.hpp b/src/buildtool/execution_engine/traverser/traverser.hpp
index 2567f3a4..bc09dc72 100644
--- a/src/buildtool/execution_engine/traverser/traverser.hpp
+++ b/src/buildtool/execution_engine/traverser/traverser.hpp
@@ -17,7 +17,7 @@
 
 #include <atomic>
 
-#include "gsl-lite/gsl-lite.hpp"
+#include "gsl/gsl"
 #include "src/buildtool/execution_engine/dag/dag.hpp"
 #include "src/buildtool/logging/logger.hpp"
 #include "src/buildtool/multithreading/task_system.hpp"
@@ -46,11 +46,8 @@ class Traverser {
     Traverser(Executor const& r,
               DependencyGraph const& graph,
               std::size_t jobs,
-              gsl::not_null<std::atomic<bool>*> fail_flag)
-        : runner_{r},
-          graph_{graph},
-          failed_{std::move(fail_flag)},
-          tasker_{jobs} {}
+              gsl::not_null<std::atomic<bool>*> const& fail_flag)
+        : runner_{r}, graph_{graph}, failed_{fail_flag}, tasker_{jobs} {}
     Traverser() = delete;
     Traverser(Traverser const&) = delete;
     Traverser(Traverser&&) = delete;