1 files changed, 5 insertions, 5 deletions
diff --git a/extern/ceres/internal/ceres/scoped_thread_token.h b/extern/ceres/internal/ceres/scoped_thread_token.h
index c167397cce9..533bfd5a387 100644
--- a/extern/ceres/internal/ceres/scoped_thread_token.h
+++ b/extern/ceres/internal/ceres/scoped_thread_token.h
@@ -31,6 +31,7 @@
 #ifndef CERES_INTERNAL_SCOPED_THREAD_TOKEN_H_
 #define CERES_INTERNAL_SCOPED_THREAD_TOKEN_H_
 
+#include "ceres/internal/export.h"
 #include "ceres/thread_token_provider.h"
 
 namespace ceres {
@@ -38,21 +39,20 @@ namespace internal {
 
 // Helper class for ThreadTokenProvider. This object acquires a token in its
 // constructor and puts that token back with destruction.
-class ScopedThreadToken {
+class CERES_NO_EXPORT ScopedThreadToken {
  public:
-  ScopedThreadToken(ThreadTokenProvider* provider)
+  explicit ScopedThreadToken(ThreadTokenProvider* provider)
       : provider_(provider), token_(provider->Acquire()) {}
 
   ~ScopedThreadToken() { provider_->Release(token_); }
+  ScopedThreadToken(ScopedThreadToken&) = delete;
+  ScopedThreadToken& operator=(ScopedThreadToken&) = delete;
 
   int token() const { return token_; }
 
  private:
   ThreadTokenProvider* provider_;
   int token_;
-
-  ScopedThreadToken(ScopedThreadToken&);
-  ScopedThreadToken& operator=(ScopedThreadToken&);
 };
 
 }  // namespace internal