Add error

include/libipc/imp/error.h

@@ -0,0 +1,27 @@
+/**
+ * \file libipc/error.h
+ * \author mutouyun (orz@orzz.org)
+ * \brief A platform-dependent error code.
+ */
+#pragma once
+
+#include <system_error>
+#include <string>
+#include <cstdint>
+
+#include "libipc/imp/export.h"
+#include "libipc/imp/fmt_cpo.h"
+
+namespace ipc {
+
+/**
+ * \brief Custom defined fmt_to method for imp::fmt
+ */
+namespace detail_tag_invoke {
+
+inline bool tag_invoke(decltype(ipc::fmt_to), fmt_context &ctx, std::error_code const &ec) noexcept {
+  return fmt_to(ctx, '[', ec.value(), ": ", ec.message(), ']');
+}
+
+} // namespace detail_tag_invoke
+} // namespace ipc

test/imp/test_imp_error.cpp

@@ -0,0 +1,12 @@
+#include <iostream>
+
+#include "test.h"
+
+#include "libipc/imp/error.h"
+#include "libipc/imp/fmt.h"
+
+TEST(error, error_code) {
+  std::error_code ecode;
+  EXPECT_FALSE(ecode);
+  std::cout << ipc::fmt(ecode, '\n');
+}