Add a user interface with a custom name prefix.

Author: mutouyun

include/libipc/def.h

@@ -65,4 +65,9 @@ struct relat_trait<wr<Rp, Rc, Ts>> {
 template <template <typename> class Policy, typename Flag>
 struct relat_trait<Policy<Flag>> : relat_trait<Flag> {};
 
+// the prefix tag of a channel
+struct prefix {
+    char const *str;
+};
+
 } // namespace ipc

include/libipc/ipc.h

@@ -22,6 +22,7 @@ struct IPC_EXPORT chan_impl {
     static ipc::handle_t inited();
 
     static bool connect   (ipc::handle_t * ph, char const * name, unsigned mode);
+    static bool connect   (ipc::handle_t * ph, prefix, char const * name, unsigned mode);
     static bool reconnect (ipc::handle_t * ph, unsigned mode);
     static void disconnect(ipc::handle_t h);
     static void destroy   (ipc::handle_t h);
@@ -54,6 +55,10 @@ class chan_wrapper {
         : connected_{this->connect(name, mode)} {
     }
 
+    chan_wrapper(prefix pref, char const * name, unsigned mode = ipc::sender)
+        : connected_{this->connect(pref, name, mode)} {
+    }
+
     chan_wrapper(chan_wrapper&& rhs) noexcept
         : chan_wrapper{} {
         swap(rhs);
@@ -102,6 +107,11 @@ class chan_wrapper {
         detail_t::disconnect(h_); // clear old connection
         return connected_ = detail_t::connect(&h_, name, mode_ = mode);
     }
+    bool connect(prefix pref, char const * name, unsigned mode = ipc::sender | ipc::receiver) {
+        if (name == nullptr || name[0] == '\0') return false;
+        detail_t::disconnect(h_); // clear old connection
+        return connected_ = detail_t::connect(&h_, pref, name, mode_ = mode);
+    }
 
     /**
      * Try connecting with new mode flags.

src/libipc/circ/elem_array.h

@@ -37,8 +37,8 @@ class elem_array : public ipc::circ::conn_head<Policy> {
     elem_t   block_[elem_max] {};
 
     /**
-     * @remarks 'warning C4348: redefinition of default parameter' with MSVC.
-     * @see
+     * \remarks 'warning C4348: redefinition of default parameter' with MSVC.
+     * \see
      *  - https://stackoverflow.com/questions/12656239/redefinition-of-default-template-parameter
      *  - https://developercommunity.visualstudio.com/content/problem/425978/incorrect-c4348-warning-in-nested-template-declara.html
     */