Fix CI on develop after #5600, #5607, and #5755

- binary_reader: cast the result of -1 - number back to number_integer_t,
  because a number_integer_t narrower than int is promoted to int, which
  GCC's -Warith-conversion rejects (ci_test_gcc, ci_test_standards_gcc)
- JSON_DELETE_DEPRECATED_FUNCTIONS: declare the deleted stream operators
  as function templates at namespace scope, because GCC < 5 rejects deleted
  friend functions ("can't initialize friend function") and Clang 7-9 report
  a redefinition when a class template has a deleted friend function
- docs: give the examples of JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS "Example:"
  titles and add the page to the docset (style_check)

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

docs/docset/docSet.sql

@@ -250,6 +250,7 @@ INSERT INTO searchIndex(name, type, path) VALUES ('JSON_TRY_USER', 'Macro', 'api
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_USE_GLOBAL_UDLS', 'Macro', 'api/macros/json_use_global_udls/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_USE_IMPLICIT_CONVERSIONS', 'Macro', 'api/macros/json_use_implicit_conversions/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON', 'Macro', 'api/macros/json_use_legacy_discarded_value_comparison/index.html');
+INSERT INTO searchIndex(name, type, path) VALUES ('JSON_USE_OBJECTS_FOR_ENUM_KEYED_MAPS', 'Macro', 'api/macros/json_use_objects_for_enum_keyed_maps/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_USE_SIMDUTF', 'Macro', 'api/macros/json_use_simdutf/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('Macros', 'Macro', 'api/macros/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE', 'Macro', 'api/macros/nlohmann_define_derived_type/index.html');

docs/mkdocs/docs/api/macros/json_use_objects_for_enum_keyed_maps.md

@@ -69,7 +69,7 @@ The default value is `0` (disabled — existing behavior is preserved).
 
 ## Examples
 
-??? example "Default behavior (macro not defined)"
+??? example "Example: default behavior (macro not defined)"
 
     Without the macro, a map with enum keys is stored as an array of pairs:
 
@@ -96,7 +96,7 @@ The default value is `0` (disabled — existing behavior is preserved).
     }
     ```
 
-??? example "Objects for enum-keyed maps (macro defined to 1)"
+??? example "Example: objects for enum-keyed maps (macro defined to 1)"
 
     With the macro, the same map is stored as an object:
 

include/nlohmann/detail/input/binary_reader.hpp

@@ -662,10 +662,11 @@ class binary_reader
         }
 
         // the value is -1 - number, which fits into number_integer_t
-        // whenever number does
+        // whenever number does; the outer cast undoes the integral promotion
+        // for number_integer_t types narrower than int
         if (JSON_HEDLEY_LIKELY(value_in_range_of<number_integer_t>(number)))
         {
-            return sax->number_integer(static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(number));
+            return sax->number_integer(conditional_static_cast<number_integer_t>(static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(number)));
         }
 
         // like the lexer does for JSON text, store a value too small for

include/nlohmann/json.hpp

@@ -5319,6 +5319,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         return o;
     }
 
+#if !JSON_DELETE_DEPRECATED_FUNCTIONS
+    // the deleted version is a function template after the class, because
+    // GCC < 5 and Clang < 10 reject deleted friend functions in class templates
     /// @brief serialize to stream
     /// @sa https://json.nlohmann.me/api/operator_ltlt/
     /// @deprecated This function is deprecated since 3.0.0 and will be removed in
@@ -5327,9 +5330,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     ///             replace calls like `j >> o;` with `o << j;`.
     JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator<<(std::ostream&, const basic_json&))
     friend std::ostream& operator>>(const basic_json& j, std::ostream& o)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return o << j;
     }
@@ -5507,6 +5507,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 #pragma clang diagnostic pop
 #endif
 #ifndef JSON_NO_IO
+#if !JSON_DELETE_DEPRECATED_FUNCTIONS
+    // the deleted version is a function template after the class, because
+    // GCC < 5 and Clang < 10 reject deleted friend functions in class templates
     /// @brief deserialize from stream
     /// @sa https://json.nlohmann.me/api/operator_gtgt/
     /// @deprecated This stream operator is deprecated since 3.0.0 and will be removed in
@@ -5515,9 +5518,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     ///             replace calls like `j << i;` with `i >> j;`.
     JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator>>(std::istream&, basic_json&))
     friend std::istream& operator<<(basic_json& j, std::istream& i)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return operator>>(i, j);
     }
@@ -7178,6 +7178,18 @@ std::string format_as(const NLOHMANN_BASIC_JSON_TPL& j)
     return j.dump();
 }
 
+#if JSON_DELETE_DEPRECATED_FUNCTIONS && !defined(JSON_NO_IO)
+    /// @brief serialize to stream (deleted; use operator<<(std::ostream&, const basic_json&))
+    /// @sa https://json.nlohmann.me/api/operator_ltlt/
+    NLOHMANN_BASIC_JSON_TPL_DECLARATION
+    std::ostream& operator>>(const NLOHMANN_BASIC_JSON_TPL& j, std::ostream& o) = delete;
+
+    /// @brief deserialize from stream (deleted; use operator>>(std::istream&, basic_json&))
+    /// @sa https://json.nlohmann.me/api/operator_gtgt/
+    NLOHMANN_BASIC_JSON_TPL_DECLARATION
+    std::istream& operator<<(NLOHMANN_BASIC_JSON_TPL& j, std::istream& i) = delete;
+#endif
+
 NLOHMANN_JSON_NAMESPACE_END
 
 ///////////////////////

single_include/nlohmann/json.hpp

@@ -14353,10 +14353,11 @@ class binary_reader
         }
 
         // the value is -1 - number, which fits into number_integer_t
-        // whenever number does
+        // whenever number does; the outer cast undoes the integral promotion
+        // for number_integer_t types narrower than int
         if (JSON_HEDLEY_LIKELY(value_in_range_of<number_integer_t>(number)))
         {
-            return sax->number_integer(static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(number));
+            return sax->number_integer(conditional_static_cast<number_integer_t>(static_cast<number_integer_t>(-1) - static_cast<number_integer_t>(number)));
         }
 
         // like the lexer does for JSON text, store a value too small for
@@ -32469,6 +32470,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         return o;
     }
 
+#if !JSON_DELETE_DEPRECATED_FUNCTIONS
+    // the deleted version is a function template after the class, because
+    // GCC < 5 and Clang < 10 reject deleted friend functions in class templates
     /// @brief serialize to stream
     /// @sa https://json.nlohmann.me/api/operator_ltlt/
     /// @deprecated This function is deprecated since 3.0.0 and will be removed in
@@ -32477,9 +32481,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     ///             replace calls like `j >> o;` with `o << j;`.
     JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator<<(std::ostream&, const basic_json&))
     friend std::ostream& operator>>(const basic_json& j, std::ostream& o)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return o << j;
     }
@@ -32657,6 +32658,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
 #pragma clang diagnostic pop
 #endif
 #ifndef JSON_NO_IO
+#if !JSON_DELETE_DEPRECATED_FUNCTIONS
+    // the deleted version is a function template after the class, because
+    // GCC < 5 and Clang < 10 reject deleted friend functions in class templates
     /// @brief deserialize from stream
     /// @sa https://json.nlohmann.me/api/operator_gtgt/
     /// @deprecated This stream operator is deprecated since 3.0.0 and will be removed in
@@ -32665,9 +32669,6 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     ///             replace calls like `j << i;` with `i >> j;`.
     JSON_HEDLEY_DEPRECATED_FOR(3.0.0, operator>>(std::istream&, basic_json&))
     friend std::istream& operator<<(basic_json& j, std::istream& i)
-#if JSON_DELETE_DEPRECATED_FUNCTIONS
-        = delete;
-#else
     {
         return operator>>(i, j);
     }
@@ -34328,6 +34329,18 @@ std::string format_as(const NLOHMANN_BASIC_JSON_TPL& j)
     return j.dump();
 }
 
+#if JSON_DELETE_DEPRECATED_FUNCTIONS && !defined(JSON_NO_IO)
+    /// @brief serialize to stream (deleted; use operator<<(std::ostream&, const basic_json&))
+    /// @sa https://json.nlohmann.me/api/operator_ltlt/
+    NLOHMANN_BASIC_JSON_TPL_DECLARATION
+    std::ostream& operator>>(const NLOHMANN_BASIC_JSON_TPL& j, std::ostream& o) = delete;
+
+    /// @brief deserialize from stream (deleted; use operator>>(std::istream&, basic_json&))
+    /// @sa https://json.nlohmann.me/api/operator_gtgt/
+    NLOHMANN_BASIC_JSON_TPL_DECLARATION
+    std::istream& operator<<(NLOHMANN_BASIC_JSON_TPL& j, std::istream& i) = delete;
+#endif
+
 NLOHMANN_JSON_NAMESPACE_END
 
 ///////////////////////