Bump bundled nlohmann::json to commit 84f19d6

There is a gcc10 compilation issue that got resolved in
[acts-project#2034](nlohmann/json#2034). There has not been
a tag since this was merged so I'm bumping the bundled version to the
develop branch immediately after that PR went in.

Author: paulgessinger

thirdparty/README.md

@@ -20,7 +20,7 @@ following folders removed:
 
 ## nlohmann_json
 
-A copy of [nlohmann::json](https://github.com/nlohmann/json) v3.7.3, with the
+A copy of [nlohmann::json](https://github.com/nlohmann/json) revision 84f19d6, with the
 following folders removed:
 
 -   benchmarks

thirdparty/nlohmann_json/LICENSE.MIT

@@ -1,6 +1,6 @@
 MIT License 
 
-Copyright (c) 2013-2019 Niels Lohmann
+Copyright (c) 2013-2020 Niels Lohmann
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

thirdparty/nlohmann_json/README.md

@@ -8,15 +8,18 @@
 [![Codacy Badge](https://api.codacy.com/project/badge/Grade/f3732b3327e34358a0e9d1fe9f661f08)](https://www.codacy.com/app/nlohmann/json?utm_source=github.com&utm_medium=referral&utm_content=nlohmann/json&utm_campaign=Badge_Grade)
 [![Language grade: C/C++](https://img.shields.io/lgtm/grade/cpp/g/nlohmann/json.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/nlohmann/json/context:cpp)
 [![Fuzzing Status](https://oss-fuzz-build-logs.storage.googleapis.com/badges/json.svg)](https://bugs.chromium.org/p/oss-fuzz/issues/list?sort=-opened&can=1&q=proj:json)
-[![Try online](https://img.shields.io/badge/try-online-blue.svg)](https://wandbox.org/permlink/TarF5pPn9NtHQjhf)
+[![Try online](https://img.shields.io/badge/try-online-blue.svg)](https://wandbox.org/permlink/3lCHrFUZANONKv7a)
 [![Documentation](https://img.shields.io/badge/docs-doxygen-blue.svg)](http://nlohmann.github.io/json)
 [![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/nlohmann/json/master/LICENSE.MIT)
 [![GitHub Releases](https://img.shields.io/github/release/nlohmann/json.svg)](https://github.com/nlohmann/json/releases)
+[![GitHub Downloads](https://img.shields.io/github/downloads/nlohmann/json/total)](https://github.com/nlohmann/json/releases)
 [![GitHub Issues](https://img.shields.io/github/issues/nlohmann/json.svg)](https://github.com/nlohmann/json/issues)
 [![Average time to resolve an issue](http://isitmaintained.com/badge/resolution/nlohmann/json.svg)](http://isitmaintained.com/project/nlohmann/json "Average time to resolve an issue")
 [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/289/badge)](https://bestpractices.coreinfrastructure.org/projects/289)
+[![GitHub Sponsors](https://img.shields.io/badge/GitHub-Sponsors-ff69b4)](https://github.com/sponsors/nlohmann)
 
 - [Design goals](#design-goals)
+- [Sponsors](#sponsors)
 - [Integration](#integration)
   - [CMake](#cmake)
   - [Package Managers](#package-managers)
@@ -42,7 +45,7 @@
 
 ## Design goals
 
-There are myriads of [JSON](http://json.org) libraries out there, and each may even have its reason to exist. Our class had these design goals:
+There are myriads of [JSON](https://json.org) libraries out there, and each may even have its reason to exist. Our class had these design goals:
 
 - **Intuitive syntax**. In languages such as Python, JSON feels like a first class data type. We used all the operator magic of modern C++ to achieve the same feeling in your code. Check out the [examples below](#examples) and you'll know what I mean.
 
@@ -59,6 +62,19 @@ Other aspects were not so important to us:
 See the [contribution guidelines](https://github.com/nlohmann/json/blob/master/.github/CONTRIBUTING.md#please-dont) for more information.
 
 
+## Sponsors
+
+You can sponsor this library at [GitHub Sponsors](https://github.com/sponsors/nlohmann).
+
+### :label: Named Sponsors
+
+- [Michael Hartmann](https://github.com/reFX-Mike)
+- [Stefan Hagen](https://github.com/sthagen)
+- [Steve Sperandeo](https://github.com/homer6)
+
+Thanks everyone!
+
+
 ## Integration
 
 [`json.hpp`](https://github.com/nlohmann/json/blob/develop/single_include/nlohmann/json.hpp) is the single required file in `single_include/nlohmann` or [released here](https://github.com/nlohmann/json/releases). You need to add
@@ -157,11 +173,11 @@ If you are using the [Meson Build System](http://mesonbuild.com), add this sourc
 
 The provided meson.build can also be used as an alternative to cmake for installing `nlohmann_json` system-wide in which case a pkg-config file is installed. To use it, simply have your build system require the `nlohmann_json` pkg-config dependency. In Meson, it is preferred to use the [`dependency()`](https://mesonbuild.com/Reference-manual.html#dependency) object with a subproject fallback, rather than using the subproject directly.
 
-If you are using [Conan](https://www.conan.io/) to manage your dependencies, merely add `jsonformoderncpp/x.y.z@vthiery/stable` to your `conanfile.py`'s requires, where `x.y.z` is the release version you want to use. Please file issues [here](https://github.com/vthiery/conan-jsonformoderncpp/issues) if you experience problems with the packages.
+If you are using [Conan](https://www.conan.io/) to manage your dependencies, merely add `nlohmann_json/x.y.z` to your `conanfile`'s requires, where `x.y.z` is the release version you want to use. Please file issues [here](https://github.com/conan-io/conan-center-index/issues) if you experience problems with the packages.
 
 If you are using [Spack](https://www.spack.io/) to manage your dependencies, you can use the [`nlohmann-json` package](https://spack.readthedocs.io/en/latest/package_list.html#nlohmann-json). Please see the [spack project](https://github.com/spack/spack) for any issues regarding the packaging.
 
-If you are using [hunter](https://github.com/ruslo/hunter/) on your project for external dependencies, then you can use the [nlohmann_json package](https://docs.hunter.sh/en/latest/packages/pkg/nlohmann_json.html). Please see the hunter project for any issues regarding the packaging.
+If you are using [hunter](https://github.com/cpp-pm/hunter) on your project for external dependencies, then you can use the [nlohmann_json package](https://hunter.readthedocs.io/en/latest/packages/pkg/nlohmann_json.html). Please see the hunter project for any issues regarding the packaging.
 
 If you are using [Buckaroo](https://buckaroo.pm), you can install this library's module with `buckaroo add github.com/buckaroo-pm/nlohmann-json`. Please file issues [here](https://github.com/buckaroo-pm/nlohmann-json). There is a demo repo [here](https://github.com/njlr/buckaroo-nholmann-json-example).
 
@@ -175,7 +191,12 @@ If you are using [NuGet](https://www.nuget.org), you can use the package [nlohma
 
 If you are using [conda](https://conda.io/), you can use the package [nlohmann_json](https://github.com/conda-forge/nlohmann_json-feedstock) from [conda-forge](https://conda-forge.org) executing `conda install -c conda-forge nlohmann_json`. Please file issues [here](https://github.com/conda-forge/nlohmann_json-feedstock/issues).
 
-If you are using [MSYS2](http://www.msys2.org/), your can use the [mingw-w64-nlohmann_json](https://packages.msys2.org/base/mingw-w64-nlohmann_json) package, just type `pacman -S mingw-w64-i686-nlohmann_json` or `pacman -S mingw-w64-x86_64-nlohmann_json` for installation. Please file issues [here](https://github.com/msys2/MINGW-packages/issues/new?title=%5Bnlohmann_json%5D) if you experience problems with the packages.
+If you are using [MSYS2](http://www.msys2.org/), your can use the [mingw-w64-nlohmann-json](https://packages.msys2.org/base/mingw-w64-nlohmann-json) package, just type `pacman -S mingw-w64-i686-nlohmann-json` or `pacman -S mingw-w64-x86_64-nlohmann-json` for installation. Please file issues [here](https://github.com/msys2/MINGW-packages/issues/new?title=%5Bnlohmann-json%5D) if you experience problems with the packages.
+
+If you are using [`build2`](https://build2.org), you can use the [`nlohmann-json`](https://cppget.org/nlohmann-json) package from the public repository http://cppget.org or directly from the [package's sources repository](https://github.com/build2-packaging/nlohmann-json). In your project's `manifest` file, just add `depends: nlohmann-json` (probably with some [version constraints](https://build2.org/build2-toolchain/doc/build2-toolchain-intro.xhtml#guide-add-remove-deps)). If you are not familiar with using dependencies in `build2`, [please read this introduction](https://build2.org/build2-toolchain/doc/build2-toolchain-intro.xhtml).
+Please file issues [here](https://github.com/build2-packaging/nlohmann-json) if you experience problems with the packages.
+
+If you are using [`wsjcpp`](http://wsjcpp.org), you can use the command `wsjcpp install "https://github.com/nlohmann/json:develop"` to get the latest version. Note you can change the branch ":develop" to an existing tag or another branch.
 
 ## Examples
 
@@ -283,7 +304,7 @@ auto j2 = R"(
 
 Note that without appending the `_json` suffix, the passed string literal is not parsed, but just used as JSON string value. That is, `json j = "{ \"happy\": true, \"pi\": 3.141 }"` would just store the string `"{ "happy": true, "pi": 3.141 }"` rather than parsing the actual object.
 
-The above example can also be expressed explicitly using [`json::parse()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_afd4ef1ac8ad50a5894a9afebca69140a.html#afd4ef1ac8ad50a5894a9afebca69140a):
+The above example can also be expressed explicitly using [`json::parse()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a265a473e939184aa42655c9ccdf34e58.html#a265a473e939184aa42655c9ccdf34e58):
 
 ```cpp
 // parse explicitly
@@ -294,7 +315,7 @@ You can also get a string representation of a JSON value (serialize):
 
 ```cpp
 // explicit conversion to string
-std::string s = j.dump();    // {\"happy\":true,\"pi\":3.141}
+std::string s = j.dump();    // {"happy":true,"pi":3.141}
 
 // serialization with pretty printing
 // pass in the amount of spaces to indent
@@ -450,7 +471,7 @@ j[1] = 42;
 bool foo = j.at(2);
 
 // comparison
-j == "[\"foo\", 1, true]"_json;  // true
+j == "[\"foo\", 42, true]"_json;  // true
 
 // other stuff
 j.size();     // 3 entries
@@ -1054,14 +1075,11 @@ The following compilers are currently used in continuous integration at [Travis]
 | Clang 5.0.2           | Ubuntu 14.04.1 LTS           | clang version 5.0.2-svn328729-1~exp1~20180509123505.100 (branches/release_50) |
 | Clang 6.0.1           | Ubuntu 14.04.1 LTS           | clang version 6.0.1-svn334776-1~exp1~20180726133705.85 (branches/release_60) |
 | Clang 7.0.1           | Ubuntu 14.04.1 LTS           | clang version 7.0.1-svn348686-1~exp1~20181213084532.54 (branches/release_70) |
-| Clang Xcode 8.3       | OSX 10.11.6                  | Apple LLVM version 8.1.0 (clang-802.0.38) |
-| Clang Xcode 9.0       | OSX 10.12.6                  | Apple LLVM version 9.0.0 (clang-900.0.37) |
-| Clang Xcode 9.1       | OSX 10.12.6                  | Apple LLVM version 9.0.0 (clang-900.0.38) |
-| Clang Xcode 9.2       | OSX 10.13.3                  | Apple LLVM version 9.1.0 (clang-902.0.39.1) |
 | Clang Xcode 9.3       | OSX 10.13.3                  | Apple LLVM version 9.1.0 (clang-902.0.39.2) |
 | Clang Xcode 10.0      | OSX 10.13.3                  | Apple LLVM version 10.0.0 (clang-1000.11.45.2) |
 | Clang Xcode 10.1      | OSX 10.13.3                  | Apple LLVM version 10.0.0 (clang-1000.11.45.5) |
 | Clang Xcode 10.2      | OSX 10.14.4                  | Apple LLVM version 10.0.1 (clang-1001.0.46.4) |
+| Clang Xcode 11.2.1    | OSX 10.14.4                  | Apple LLVM version 11.0.0 (clang-1100.0.33.12) |
 | Visual Studio 14 2015 | Windows Server 2012 R2 (x64) | Microsoft (R) Build Engine version 14.0.25420.1, MSVC 19.0.24215.1 |
 | Visual Studio 15 2017 | Windows Server 2012 R2 (x64) | Microsoft (R) Build Engine version 15.9.21+g9802d43bc3, MSVC 19.16.27032.1 |
 | Visual Studio 16 2019 | Windows Server 2012 R2 (x64) | Microsoft (R) Build Engine version 16.3.1+1def00d3d, MSVC 19.23.28106.4 |
@@ -1300,7 +1318,7 @@ The library itself consists of a single header file licensed under the MIT licen
 - [**AppVeyor**](https://www.appveyor.com) for [continuous integration](https://ci.appveyor.com/project/nlohmann/json) on Windows
 - [**Artistic Style**](http://astyle.sourceforge.net) for automatic source code indentation
 - [**CircleCI**](http://circleci.com) for [continuous integration](https://circleci.com/gh/nlohmann/json).
-- [**Clang**](http://clang.llvm.org) for compilation with code sanitizers
+- [**Clang**](https://clang.llvm.org) for compilation with code sanitizers
 - [**CMake**](https://cmake.org) for build automation
 - [**Codacity**](https://www.codacy.com) for further [code analysis](https://www.codacy.com/app/nlohmann/json)
 - [**Coveralls**](https://coveralls.io) to measure [code coverage](https://coveralls.io/github/nlohmann/json)
@@ -1366,6 +1384,15 @@ This library will not support comments in the future. If you wish to use comment
 
 By default, the library does not preserve the **insertion order of object elements**. This is standards-compliant, as the [JSON standard](https://tools.ietf.org/html/rfc8259.html) defines objects as "an unordered collection of zero or more name/value pairs". If you do want to preserve the insertion order, you can specialize the object type with containers like [`tsl::ordered_map`](https://github.com/Tessil/ordered-map) ([integration](https://github.com/nlohmann/json/issues/546#issuecomment-304447518)) or [`nlohmann::fifo_map`](https://github.com/nlohmann/fifo_map) ([integration](https://github.com/nlohmann/json/issues/485#issuecomment-333652309)).
 
+### Memory Release
+
+We checked with Valgrind and the Address Sanitizer (ASAN) that there are no memory leaks. 
+
+If you find that a parsing program with this library does not release memory, please consider the following case and it maybe unrelated to this library. 
+
+**Your program is compiled with glibc.** There is a tunable threshold that glibc uses to decide whether to actually return memory to the system or whether to cache it for later reuse. If in your program you make lots of small allocations and those small allocations are not a contiguous block and are presumably below the threshold, then they will not get returned to the OS.
+Here is a related issue [#1924](https://github.com/nlohmann/json/issues/1924).
+
 ### Further notes
 
 - The code contains numerous debug **assertions** which can be switched off by defining the preprocessor macro `NDEBUG`, see the [documentation of `assert`](https://en.cppreference.com/w/cpp/error/assert). In particular, note [`operator[]`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a233b02b0839ef798942dd46157cc0fe6.html#a233b02b0839ef798942dd46157cc0fe6) implements **unchecked access** for const objects: If the given key is not present, the behavior is undefined (think of a dereferenced null pointer) and yields an [assertion failure](https://github.com/nlohmann/json/issues/289) if assertions are switched on. If you are not sure whether an element in an object exists, use checked access with the [`at()` function](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a73ae333487310e3302135189ce8ff5d8.html#a73ae333487310e3302135189ce8ff5d8).

thirdparty/nlohmann_json/appveyor.yml

@@ -85,7 +85,7 @@ environment:
     - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
       configuration: Release
       platform: x64
-      CXX_FLAGS: "/permissive- /std:c++latest /utf-8 /F4000000"
+      CXX_FLAGS: "/permissive- /std:c++latest /Zc:__cplusplus /utf-8 /F4000000"
       LINKER_FLAGS: "/STACK:4000000"
       GENERATOR: Visual Studio 15 2017