Adding 4.8 test to travis

.github/CONTRIBUTING.md

@@ -54,7 +54,7 @@ To make changes, you need to edit the following files:
 
 ## Please don't
 
-- The C++11 support varies between different **compilers** and versions. Please note the [list of supported compilers](https://github.com/nlohmann/json/blob/master/README.md#supported-compilers). Some compilers like GCC 4.8 (and earlier), Clang 3.3 (and earlier), or Microsoft Visual Studio 13.0 and earlier are known not to work due to missing or incomplete C++11 support. Please refrain from proposing changes that work around these compiler's limitations with `#ifdef`s or other means.
+- The C++11 support varies between different **compilers** and versions. Please note the [list of supported compilers](https://github.com/nlohmann/json/blob/master/README.md#supported-compilers). Some compilers like GCC 4.7 (and earlier), Clang 3.3 (and earlier), or Microsoft Visual Studio 13.0 and earlier are known not to work due to missing or incomplete C++11 support. Please refrain from proposing changes that work around these compiler's limitations with `#ifdef`s or other means.
 - Specifically, I am aware of compilation problems with **Microsoft Visual Studio** (there even is an [issue label](https://github.com/nlohmann/json/issues?utf8=✓&q=label%3A%22visual+studio%22+) for these kind of bugs). I understand that even in 2016, complete C++11 support isn't there yet. But please also understand that I do not want to drop features or uglify the code just to make Microsoft's sub-standard compiler happy. The past has shown that there are ways to express the functionality such that the code compiles with the most recent MSVC - unfortunately, this is not the main objective of the project.
 - Please refrain from proposing changes that would **break [JSON](http://json.org) conformance**. If you propose a conformant extension of JSON to be supported by the library, please motivate this extension.
   - We shall not extend the library to **support comments**. There is quite some [controversy](https://www.reddit.com/r/programming/comments/4v6chu/why_json_doesnt_support_comments_douglas_crockford/) around this topic, and there were quite some [issues](https://github.com/nlohmann/json/issues/376) on this. We believe that JSON is fine without comments.

.github/PULL_REQUEST_TEMPLATE.md

@@ -13,7 +13,7 @@ Read the [Contribution Guidelines](https://github.com/nlohmann/json/blob/develop
 
 ## Please don't
 
-- The C++11 support varies between different **compilers** and versions. Please note the [list of supported compilers](https://github.com/nlohmann/json/blob/master/README.md#supported-compilers). Some compilers like GCC 4.8 (and earlier), Clang 3.3 (and earlier), or Microsoft Visual Studio 13.0 and earlier are known not to work due to missing or incomplete C++11 support. Please refrain from proposing changes that work around these compiler's limitations with `#ifdef`s or other means.
+- The C++11 support varies between different **compilers** and versions. Please note the [list of supported compilers](https://github.com/nlohmann/json/blob/master/README.md#supported-compilers). Some compilers like GCC 4.7 (and earlier), Clang 3.3 (and earlier), or Microsoft Visual Studio 13.0 and earlier are known not to work due to missing or incomplete C++11 support. Please refrain from proposing changes that work around these compiler's limitations with `#ifdef`s or other means.
 - Specifically, I am aware of compilation problems with **Microsoft Visual Studio** (there even is an [issue label](https://github.com/nlohmann/json/issues?utf8=✓&q=label%3A%22visual+studio%22+) for these kind of bugs). I understand that even in 2016, complete C++11 support isn't there yet. But please also understand that I do not want to drop features or uglify the code just to make Microsoft's sub-standard compiler happy. The past has shown that there are ways to express the functionality such that the code compiles with the most recent MSVC - unfortunately, this is not the main objective of the project.
 - Please refrain from proposing changes that would **break [JSON](http://json.org) conformance**. If you propose a conformant extension of JSON to be supported by the library, please motivate this extension.
 - Please do not open pull requests that address **multiple issues**.

.travis.yml

@@ -168,7 +168,15 @@ matrix:
 
   - os: linux
     compiler: gcc
-    env: COMPILER=g++-4.9
+    env: compiler=g++-4.8
+    addons:
+      apt:
+        sources: ['ubuntu-toolchain-r-test']
+        packages: ['g++-4.8', 'ninja-build']
+
+  - os: linux
+    compiler: gcc
+    env: compiler=g++-4.9
     addons:
       apt:
         sources: ['ubuntu-toolchain-r-test']

README.md

@@ -843,7 +843,7 @@ json j_from_ubjson = json::from_ubjson(v_ubjson);
 
 Though it's 2018 already, the support for C++11 is still a bit sparse. Currently, the following compilers are known to work:
 
-- GCC 4.9 - 8.2 (and possibly later)
+- GCC 4.8 - 8.2 (and possibly later)
 - Clang 3.4 - 6.1 (and possibly later)
 - Intel C++ Compiler 17.0.2 (and possibly later)
 - Microsoft Visual C++ 2015 / Build Tools 14.0.25123.0 (and possibly later)
@@ -853,7 +853,7 @@ I would be happy to learn about other compilers/versions.
 
 Please note:
 
-- GCC 4.8 does not work because of two bugs ([55817](https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55817) and [57824](https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57824)) in the C++11 support. Note there is a [pull request](https://github.com/nlohmann/json/pull/212) to fix some of the issues.
+- GCC 4.8 has a bug [57824](https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57824)): multiline raw strings cannot be the arguments to macros. Don't use multiline raw strings directly in macros with this compiler.
 - Android defaults to using very old compilers and C++ libraries. To fix this, add the following to your `Application.mk`. This will switch to the LLVM C++ library, the Clang compiler, and enable C++11 and other features disabled by default.
 
     ```

test/src/unit-json_patch.cpp

@@ -63,7 +63,7 @@ TEST_CASE("JSON patch")
             // is not an error, because "a" exists, and "b" will be added to
             // its value.
             CHECK_NOTHROW(doc1.patch(patch));
-            CHECK(doc1.patch(patch) == R"(
+            auto doc1_ans = R"(
                 {
                     "a": {
                         "foo": 1,
@@ -72,7 +72,8 @@ TEST_CASE("JSON patch")
                         }
                     }
                 }
-            )"_json);
+            )"_json;
+            CHECK(doc1.patch(patch) == doc1_ans);
 
             // It is an error in this document:
             json doc2 = R"({ "q": { "bar": 2 } })"_json;

test/src/unit-regression.cpp

@@ -1427,20 +1427,26 @@ TEST_CASE("regression tests")
             }
         })"_json;
 
-        CHECK_THROWS_AS(model.patch(R"([{"op": "move",
-                         "from": "/one/two/three",
-                         "path": "/a/b/c"}])"_json), json::out_of_range&);
-        CHECK_THROWS_WITH(model.patch(R"([{"op": "move",
-                         "from": "/one/two/three",
-                         "path": "/a/b/c"}])"_json),
+        auto p1 = R"([{"op": "move",
+                       "from": "/one/two/three",
+                       "path": "/a/b/c"}])"_json;
+        CHECK_THROWS_AS(model.patch(p1), json::out_of_range&);
+
+        auto p2 = R"([{"op": "move",
+                       "from": "/one/two/three",
+                       "path": "/a/b/c"}])"_json;
+        CHECK_THROWS_WITH(model.patch(p2),
                           "[json.exception.out_of_range.403] key 'a' not found");
 
-        CHECK_THROWS_AS(model.patch(R"([{"op": "copy",
-                                 "from": "/one/two/three",
-                                 "path": "/a/b/c"}])"_json), json::out_of_range&);
-        CHECK_THROWS_WITH(model.patch(R"([{"op": "copy",
+        auto p3 = R"([{"op": "copy",
+                       "from": "/one/two/three",
+                       "path": "/a/b/c"}])"_json;
+        CHECK_THROWS_AS(model.patch(p3), json::out_of_range&);
+
+        auto p4 = R"([{"op": "copy",
                                  "from": "/one/two/three",
-                                 "path": "/a/b/c"}])"_json),
+                                 "path": "/a/b/c"}])"_json;
+        CHECK_THROWS_WITH(model.patch(p4),
                           "[json.exception.out_of_range.403] key 'a' not found");
     }
 

test/src/unit-testsuites.cpp

@@ -405,7 +405,7 @@ TEST_CASE("RFC 7159 examples")
     SECTION("13 Examples")
     {
         {
-            CHECK_NOTHROW(json(R"(
+            auto json_contents = R"(
             {
                  "Image": {
                      "Width":  800,
@@ -420,11 +420,13 @@ TEST_CASE("RFC 7159 examples")
                      "IDs": [116, 943, 234, 38793]
                    }
                }
-            )"));
+            )";
+
+            CHECK_NOTHROW(json(json_contents));
         }
 
         {
-            CHECK_NOTHROW(json(R"(
+            auto json_contents = R"(
                 [
                     {
                        "precision": "zip",
@@ -446,7 +448,8 @@ TEST_CASE("RFC 7159 examples")
                        "Zip":       "94085",
                        "Country":   "US"
                     }
-            ])"));
+            ])";
+            CHECK_NOTHROW(json(json_contents));
         }
 
         CHECK(json::parse("\"Hello world!\"") == json("Hello world!"));