From 46680c87a8e400c8ba221c51d2d24fe93e58840c Mon Sep 17 00:00:00 2001
From: 0xFEEDC0DE64 <daniel@brunner.ninja>
Date: Tue, 25 May 2021 15:15:44 +0200
Subject: [PATCH] Added RefWhenNeeded

---
 CMakeLists.txt      |  1 +
 cpputils_src.pri    |  1 +
 src/refwhenneeded.h | 29 +++++++++++++++++++++++++++++
 3 files changed, 31 insertions(+)
 create mode 100644 src/refwhenneeded.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index db3a76b..cb29dca 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,6 +9,7 @@ set(headers
     src/cpptypesafeenum.h
     src/cpputils.h
     src/delayedconstruction.h
+    src/refwhenneeded.h
     src/strutils.h
 )
 
diff --git a/cpputils_src.pri b/cpputils_src.pri
index 7fc0df9..2f77f6f 100644
--- a/cpputils_src.pri
+++ b/cpputils_src.pri
@@ -8,6 +8,7 @@ HEADERS += \
     $$PWD/src/cpptypesafeenum.h \
     $$PWD/src/cpputils.h \
     $$PWD/src/delayedconstruction.h \
+    $$PWD/src/refwhenneeded.h \
     $$PWD/src/strutils.h
 
 SOURCES += \
diff --git a/src/refwhenneeded.h b/src/refwhenneeded.h
new file mode 100644
index 0000000..30994ed
--- /dev/null
+++ b/src/refwhenneeded.h
@@ -0,0 +1,29 @@
+#pragma once
+
+// system includes
+#include <cstdint>
+
+namespace cpputils {
+template<typename X> struct RefWhenNeeded      { using T = const X &;     RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+template<> struct RefWhenNeeded<bool>          { using T = bool;          RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+template<> struct RefWhenNeeded<int8_t>        { using T = int8_t;        RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+template<> struct RefWhenNeeded<uint8_t>       { using T = uint8_t;       RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+template<> struct RefWhenNeeded<int16_t>       { using T = int16_t;       RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+template<> struct RefWhenNeeded<uint16_t>      { using T = uint16_t;      RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+template<> struct RefWhenNeeded<int32_t>       { using T = int32_t;       RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+template<> struct RefWhenNeeded<uint32_t>      { using T = uint32_t;      RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+template<> struct RefWhenNeeded<int64_t>       { using T = int64_t;       RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+template<> struct RefWhenNeeded<uint64_t>      { using T = uint64_t;      RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+template<> struct RefWhenNeeded<long>          { using T = long;          RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+template<> struct RefWhenNeeded<unsigned long> { using T = unsigned long; RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+template<> struct RefWhenNeeded<float>         { using T = float;         RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+template<> struct RefWhenNeeded<double>        { using T = double;        RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+
+//template<typename X> struct RefWhenNeeded                       { using T = X;                                      RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+//template<> struct RefWhenNeeded<JsonObjectConst>                { using T = const JsonObjectConst &;                RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+//template<> struct RefWhenNeeded<std::optional<JsonObjectConst>> { using T = const std::optional<JsonObjectConst> &; RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+//template<> struct RefWhenNeeded<JsonArrayConst>                 { using T = const JsonArrayConst &;                 RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+//template<> struct RefWhenNeeded<JsonVariantConst>               { using T = const JsonVariantConst &;               RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+//template<> struct RefWhenNeeded<std::string>                    { using T = const std::string &;                    RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+//template<> struct RefWhenNeeded<std::optional<uint32_t>>        { using T = const std::optional<uint32_t> &;        RefWhenNeeded() = delete; ~RefWhenNeeded() = delete; };
+} // namespace cpputils