From 73b8a6a9c88a4de80b37bb54603d5fe56be73960 Mon Sep 17 00:00:00 2001
From: Niels Lohmann <mail@nlohmann.me>
Date: Thu, 1 Oct 2026 14:16:08 +0200
Subject: [PATCH] Add DisableTupleReferenceConversion to Meson and the CMake
 pkg-config file

JSON_DisableTupleReferenceConversion (#5598) came in with the develop
merge. Meson gets the matching option, and both the Meson and the CMake
pkg-config file carry JSON_DISABLE_TUPLE_REFERENCE_CONVERSION=1 when it
is enabled. The ci_meson_install job checks it.

Reported by @heitbaum in #5587.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---
 .github/workflows/ubuntu.yml                     | 5 +++--
 CMakeLists.txt                                   | 3 +++
 docs/mkdocs/docs/integration/package_managers.md | 4 ++--
 meson.build                                      | 3 +++
 meson_options.txt                                | 6 ++++++
 5 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index 68656a43c..3b003b47d 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -51,7 +51,7 @@ jobs:
           cmake --build build-import
       - name: Install with Meson and non-default options
         run: |
-          meson setup build-meson-options --prefix=${{ github.workspace }}/install-options -DMultipleHeaders=true -DDiagnostics=true -DGlobalUDLs=false
+          meson setup build-meson-options --prefix=${{ github.workspace }}/install-options -DMultipleHeaders=true -DDiagnostics=true -DGlobalUDLs=false -DDisableTupleReferenceConversion=true
           meson install -C build-meson-options
       - name: Check that the options reach the installed files
         run: |
@@ -60,7 +60,8 @@ jobs:
           echo "$cflags"
           echo "$cflags" | grep -q -- '-DJSON_DIAGNOSTICS=1'
           echo "$cflags" | grep -q -- '-DJSON_USE_GLOBAL_UDLS=0'
-          grep -q 'JSON_USE_GLOBAL_UDLS=0;JSON_DIAGNOSTICS=1' install-options/share/cmake/nlohmann_json/nlohmann_jsonTargets.cmake
+          echo "$cflags" | grep -q -- '-DJSON_DISABLE_TUPLE_REFERENCE_CONVERSION=1'
+          grep -q 'JSON_USE_GLOBAL_UDLS=0;JSON_DISABLE_TUPLE_REFERENCE_CONVERSION=1;JSON_DIAGNOSTICS=1' install-options/share/cmake/nlohmann_json/nlohmann_jsonTargets.cmake
           cmake -S tests/cmake_import/project -B build-import-options -DCMAKE_PREFIX_PATH=${{ github.workspace }}/install-options
           cmake --build build-import-options
       - name: Install with Meson and the include directory outside the prefix
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5204ff1ed..5c3864359 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -186,6 +186,9 @@ endif()
 if (JSON_DisableEnumSerialization)
     string(APPEND NLOHMANN_JSON_PKGCONFIG_CFLAGS " -DJSON_DISABLE_ENUM_SERIALIZATION=1")
 endif()
+if (JSON_DisableTupleReferenceConversion)
+    string(APPEND NLOHMANN_JSON_PKGCONFIG_CFLAGS " -DJSON_DISABLE_TUPLE_REFERENCE_CONVERSION=1")
+endif()
 if (JSON_Diagnostics)
     string(APPEND NLOHMANN_JSON_PKGCONFIG_CFLAGS " -DJSON_DIAGNOSTICS=1")
 endif()
diff --git a/docs/mkdocs/docs/integration/package_managers.md b/docs/mkdocs/docs/integration/package_managers.md
index b63adee76..a1b67c908 100644
--- a/docs/mkdocs/docs/integration/package_managers.md
+++ b/docs/mkdocs/docs/integration/package_managers.md
@@ -128,8 +128,8 @@ subproject fallback, rather than using the subproject directly.
 
 The options that change the library's configuration are available in Meson as well, named like the
 [CMake options](cmake.md#cmake-options) without the `JSON_` prefix: `MultipleHeaders`, `GlobalUDLs`,
-`ImplicitConversions`, `DisableEnumSerialization`, `Diagnostics`, `Diagnostic_Positions`,
-`LegacyDiscardedValueComparison`, and `StrictNulHandling`. They have the same defaults as in CMake, except that
+`ImplicitConversions`, `DisableEnumSerialization`, `DisableTupleReferenceConversion`, `Diagnostics`,
+`Diagnostic_Positions`, `LegacyDiscardedValueComparison`, and `StrictNulHandling`. They have the same defaults as in CMake, except that
 `MultipleHeaders` is `false`. Set them with `-D` when setting up the build, or with the subproject name as prefix when
 the library is used as a subproject:
 
diff --git a/meson.build b/meson.build
index 33b2ff466..2ece2ab42 100644
--- a/meson.build
+++ b/meson.build
@@ -24,6 +24,9 @@ endif
 if get_option('DisableEnumSerialization')
     json_defines += 'JSON_DISABLE_ENUM_SERIALIZATION=1'
 endif
+if get_option('DisableTupleReferenceConversion')
+    json_defines += 'JSON_DISABLE_TUPLE_REFERENCE_CONVERSION=1'
+endif
 if get_option('Diagnostics')
     json_defines += 'JSON_DIAGNOSTICS=1'
 endif
diff --git a/meson_options.txt b/meson_options.txt
index ebb19bb40..5f38c5105 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -22,6 +22,12 @@ option(
     value: false,
     description: 'Disable default integer enum serialization',
 )
+option(
+    'DisableTupleReferenceConversion',
+    type: 'boolean',
+    value: false,
+    description: 'Disable conversion from a one-element tuple of a JSON reference',
+)
 option(
     'Diagnostics',
     type: 'boolean',