util/Error: add bridge to std::exception

src/Log.cxx

@@ -29,9 +29,6 @@
 #include <string.h>
 #include <errno.h>
 
-/** Domain for std::exception */
-static constexpr Domain exception_domain("exception");
-
 void
 LogFormatV(const Domain &domain, LogLevel level, const char *fmt, va_list ap)
 {

src/util/Error.cxx

@@ -31,6 +31,9 @@
 #include "Error.hxx"
 #include "Domain.hxx"
 
+#include <exception>
+#include <system_error>
+
 #ifdef WIN32
 #include <windows.h>
 #endif
@@ -40,6 +43,8 @@
 #include <stdio.h>
 #include <string.h>
 
+const Domain exception_domain("exception");
+
 const Domain errno_domain("errno");
 
 #ifdef WIN32
@@ -48,6 +53,26 @@ const Domain win32_domain("win32");
 
 Error::~Error() {}
 
+void
+Error::Set(const std::exception &src)
+{
+	try {
+		/* classify the exception */
+		throw src;
+	} catch (const std::system_error &se) {
+		if (se.code().category() == std::system_category()) {
+#ifdef WIN32
+			Set(win32_domain, se.code().value(), se.what());
+#else
+			Set(errno_domain, se.code().value(), se.what());
+#endif
+		} else
+			Set(exception_domain, src.what());
+	} catch (...) {
+		Set(exception_domain, src.what());
+	}
+}
+
 void
 Error::Set(const Domain &_domain, int _code, const char *_message)
 {

src/util/Error.hxx

@@ -40,6 +40,13 @@
 
 class Domain;
 
+namespace std {
+	class exception;
+}
+
+/** Domain for std::exception */
+extern const Domain exception_domain;
+
 extern const Domain errno_domain;
 
 #ifdef WIN32
@@ -126,6 +133,8 @@ public:
 		message = other.message;
 	}
 
+	void Set(const std::exception &src);
+
 	void Set(const Domain &_domain, int _code, const char *_message);
 
 	void Set(const Domain &_domain, const char *_message) {