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, 2 deletions

diff --git a/src/buildtool/multithreading/async_map_node.hpp b/src/buildtool/multithreading/async_map_node.hpp
index c729582d..2c07f11b 100644
--- a/src/buildtool/multithreading/async_map_node.hpp
+++ b/src/buildtool/multithreading/async_map_node.hpp
@@ -19,9 +19,10 @@
 #include <mutex>
 #include <optional>
 
-#include "gsl-lite/gsl-lite.hpp"
+#include "gsl/gsl"
 #include "src/buildtool/multithreading/task.hpp"
 #include "src/buildtool/multithreading/task_system.hpp"
+#include "src/utils/cpp/gsl.hpp"
 
 // Wrapper around Value to enable async access to it in a continuation-style
 // programming way
@@ -154,7 +155,7 @@ class AsyncMapNode {
     // Not thread safe, do not use unless the value has been already set
     [[nodiscard]] auto GetValue() const& noexcept -> Value const& {
         // Will only be checked in debug build
-        gsl_ExpectsAudit(value_.has_value());
+        ExpectsAudit(value_.has_value());
         return *value_;
     }
     [[nodiscard]] auto GetValue() && noexcept = delete;