pid() is const

diff --git a/asyncio/async_process.hpp b/asyncio/async_process.hpp
index bc56b43..aed7b20 100644 (file)
--- a/asyncio/async_process.hpp
+++ b/asyncio/async_process.hpp
@@ -126,7 +126,7 @@ class ProcessImplementation : public IOImplementation
       bool kill(const Signal signal);
 
       /// returns the pid of the child process
-      pid_t pid() { return m_pid; }
+      pid_t pid() const { return m_pid; }
 
    protected: