value,reference,module_loader: Use rocket::exchange()

asteria/runtime/module_loader.hpp

@@ -73,14 +73,10 @@ class Module_Loader::Unique_Stream
     Unique_Stream&
     do_reset(const refcnt_ptr<Module_Loader>& loader, locked_stream_pair* strm) noexcept
       {
-        auto qloader = ::std::exchange(this->m_loader, loader);
-        auto qstrm = ::std::exchange(this->m_strm, strm);
-        if(!qstrm)
-          return *this;
-
-        // Unlock the old stream if one has been assigned.
-        ROCKET_ASSERT(qloader);
-        qloader->do_unlock_stream(qstrm);
+        auto qloader = ::rocket::exchange(this->m_loader, loader);
+        auto qstrm = ::rocket::exchange(this->m_strm, strm);
+        if(qloader && qstrm)
+          qloader->do_unlock_stream(qstrm);
         return *this;
       }
 

asteria/runtime/reference.hpp

@@ -56,7 +56,7 @@ class Reference
         m_var(::std::move(other.m_var)),
         m_ptc(::std::move(other.m_ptc)),
         m_mods(::std::move(other.m_mods)),
-        m_xref(::std::exchange(other.m_xref, xref_invalid))
+        m_xref(::rocket::exchange(other.m_xref))
       {
         if(this->m_xref == xref_temporary)
           this->m_value = ::std::move(other.m_value);
@@ -73,7 +73,7 @@ class Reference
           this->m_ptc = ::std::move(other.m_ptc);
 
         this->m_mods = ::std::move(other.m_mods);
-        this->m_xref = ::std::exchange(other.m_xref, xref_invalid);
+        this->m_xref = ::rocket::exchange(other.m_xref);
         return *this;
       }
 

asteria/value.hpp

@@ -80,7 +80,7 @@ class Value
 
     Value(Value&& other) noexcept
       :
-        m_bytes(::std::exchange(other.m_bytes, bytes_type()))  // HACK
+        m_bytes(::rocket::exchange(other.m_bytes))  // HACK
       {
       }