From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 18 Dec 2022 10:59:32 +0000 (+0200)
Subject: Disable the templated constructor of Value if the source type is Value
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=9d71185a55558c80c85a65e13427dd491a2f4451;p=libs%2Fdatafile.git

Disable the templated constructor of Value if the source type is Value

Microsoft's std::vector uses a T & (without const) for copying, which
resolves to the templated constructor instead of the copy constructor
unless the former is disabled for that signature.
---

diff --git a/source/value.h b/source/value.h
index bcddd6e..ba61181 100644
--- a/source/value.h
+++ b/source/value.h
@@ -2,6 +2,7 @@
 #define MSP_DATAFILE_VALUE_H_
 
 #include <vector>
+#include <type_traits>
 #include <msp/core/attributes.h>
 #include <msp/core/meta.h>
 #include <msp/core/variant.h>
@@ -18,7 +19,7 @@ private:
 
 public:
 	template<typename T>
-	Value(T &&d):
+	Value(T &&d, typename std::enable_if<!std::is_same<typename std::remove_reference<T>::type, Value>::value, int>::type = 0):
 		sig(TypeInfo<T>::signature),
 		data(static_cast<typename TypeInfo<T>::Store>(std::forward<T>(d)))
 	{ }