From 000c1332e30396ffa9b1c4a54444a0da38e43620 Mon Sep 17 00:00:00 2001
From: chenguoping <chenguopingdota@163.com>
Date: Mon, 22 Jun 2020 19:58:57 +0800
Subject: [PATCH 1/4] fix compiler error C2440 in  VS

---
 test/src/unit-conversions.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/test/src/unit-conversions.cpp b/test/src/unit-conversions.cpp
index 2fce369616..d966da4c9a 100644
--- a/test/src/unit-conversions.cpp
+++ b/test/src/unit-conversions.cpp
@@ -1746,7 +1746,8 @@ TEST_CASE("std::optional")
         std::vector<std::optional<int>> opt_array = {{1, 2, std::nullopt}};
 
         CHECK(json(opt_array) == j_array);
-        CHECK(std::vector<std::optional<int>>(j_array) == opt_array);
+        std::vector<std::optional<int>> tmp = j_array;
+        CHECK(tmp == opt_array);
     }
 
     SECTION("object")
@@ -1755,7 +1756,8 @@ TEST_CASE("std::optional")
         std::map<std::string, std::optional<int>> opt_object {{"one", 1}, {"two", 2}, {"zero", std::nullopt}};
 
         CHECK(json(opt_object) == j_object);
-        CHECK(std::map<std::string, std::optional<int>>(j_object) == opt_object);
+        std::map<std::string, std::optional<int>> tmp =j_object;
+        CHECK(tmp == opt_object);
     }
 }
 #endif

From 4c4af3b161521a3ed84f455f767e8524d5f80a80 Mon Sep 17 00:00:00 2001
From: chenguoping <chenguopingdota@163.com>
Date: Wed, 24 Jun 2020 09:27:08 +0800
Subject: [PATCH 2/4] add travis task : run testcases in C++17

---
 .travis.yml | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index 280c2c06c0..480797095a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -218,6 +218,17 @@ matrix:
         sources: ['ubuntu-toolchain-r-test']
         packages: ['g++-9', 'ninja-build']
 
+  - os: linux
+    compiler: gcc
+    env:
+      - COMPILER=g++-9
+      - CXXFLAGS=-std=c++17
+      - CMAKECXXSTANDARD=17
+    addons:
+      apt:
+        sources: ['ubuntu-toolchain-r-test']
+        packages: ['g++-9', 'ninja-build']
+
   # Linux / Clang
 
   - os: linux
@@ -328,7 +339,11 @@ script:
 
   # compile and execute unit tests
   - mkdir -p build && cd build
-  - cmake .. ${CMAKE_OPTIONS} -DJSON_MultipleHeaders=${MULTIPLE_HEADERS} -GNinja && cmake --build . --config Release
+  - if [[ "${CMAKECXXSTANDARD}" != "" ]]; then
+    cmake .. ${CMAKE_OPTIONS} -DJSON_MultipleHeaders=${MULTIPLE_HEADERS} -DCMAKE_CXX_STANDARD=${CMAKECXXSTANDARD} -GNinja && cmake --build . --config Release ;
+    else
+    cmake .. ${CMAKE_OPTIONS} -DJSON_MultipleHeaders=${MULTIPLE_HEADERS} -GNinja && cmake --build . --config Release ;
+    fi
   - ctest -C Release --timeout 2700 -V -j
   - cd ..
 

From e0f6c96c194c97ff9eb749979216c2d4da173067 Mon Sep 17 00:00:00 2001
From: chenguoping <chenguopingdota@163.com>
Date: Wed, 24 Jun 2020 15:18:13 +0800
Subject: [PATCH 3/4] detect the exception in testcase - SECTION("null")

---
 test/src/unit-conversions.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/test/src/unit-conversions.cpp b/test/src/unit-conversions.cpp
index d966da4c9a..476a2149d9 100644
--- a/test/src/unit-conversions.cpp
+++ b/test/src/unit-conversions.cpp
@@ -1710,7 +1710,8 @@ TEST_CASE("std::optional")
         std::optional<std::string> opt_null;
 
         CHECK(json(opt_null) == j_null);
-        CHECK(std::optional<std::string>(j_null) == std::nullopt);
+        CHECK_THROWS_WITH(std::optional<std::string>(j_null) == std::nullopt,
+                          "[json.exception.type_error.302] type must be string, but is null");
     }
 
     SECTION("string")

From 7df758f41f97a43d1b562579bd260fee94187b9d Mon Sep 17 00:00:00 2001
From: chenguoping <chenguopingdota@163.com>
Date: Sun, 28 Jun 2020 09:26:33 +0800
Subject: [PATCH 4/4] rename CMAKECXXSTANDARD by CMAKE_CXX_STANDARD

---
 .travis.yml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 480797095a..d5811eebd8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -223,7 +223,7 @@ matrix:
     env:
       - COMPILER=g++-9
       - CXXFLAGS=-std=c++17
-      - CMAKECXXSTANDARD=17
+      - CMAKE_CXX_STANDARD=17
     addons:
       apt:
         sources: ['ubuntu-toolchain-r-test']
@@ -339,8 +339,8 @@ script:
 
   # compile and execute unit tests
   - mkdir -p build && cd build
-  - if [[ "${CMAKECXXSTANDARD}" != "" ]]; then
-    cmake .. ${CMAKE_OPTIONS} -DJSON_MultipleHeaders=${MULTIPLE_HEADERS} -DCMAKE_CXX_STANDARD=${CMAKECXXSTANDARD} -GNinja && cmake --build . --config Release ;
+  - if [[ "${CMAKE_CXX_STANDARD}" != "" ]]; then
+    cmake .. ${CMAKE_OPTIONS} -DJSON_MultipleHeaders=${MULTIPLE_HEADERS} -DCMAKE_CXX_STANDARD=${CMAKE_CXX_STANDARD} -GNinja && cmake --build . --config Release ;
     else
     cmake .. ${CMAKE_OPTIONS} -DJSON_MultipleHeaders=${MULTIPLE_HEADERS} -GNinja && cmake --build . --config Release ;
     fi