Rename the emit lambda in the image writer for Qt compatibility

Qt defines emit as an empty macro, so a Qt header included before
json_view.hpp broke the lambda's declaration (see #5865). The slots
variables in the image tests are renamed as well.

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

include/nlohmann/detail/view/image.hpp

@@ -105,7 +105,7 @@ inline void compact_nodes(const document_data& d, std::size_t arena_size, std::v
         }
         return r;
     };
-    const auto emit = [&](const node * v)
+    const auto copy_node = [&](const node * v)
     {
         node r = *v;
         switch (static_cast<value_t>(v->kind))
@@ -159,7 +159,7 @@ inline void compact_nodes(const document_data& d, std::size_t arena_size, std::v
         }
         out.push_back(r);
     };
-    emit(d.nodes);
+    copy_node(d.nodes);
     while (!stack.empty())
     {
         frame& top = stack.back();
@@ -184,7 +184,7 @@ inline void compact_nodes(const document_data& d, std::size_t arena_size, std::v
             v = document_data::deref(top.cur);
             top.cur = document_data::after(top.cur);
         }
-        emit(v); // may grow the stack (top is not used afterwards)
+        copy_node(v); // may grow the stack (top is not used afterwards)
     }
 }
 

single_include/nlohmann/json_view.hpp

@@ -4623,7 +4623,7 @@ inline void compact_nodes(const document_data& d, std::size_t arena_size, std::v
         }
         return r;
     };
-    const auto emit = [&](const node * v)
+    const auto copy_node = [&](const node * v)
     {
         node r = *v;
         switch (static_cast<value_t>(v->kind))
@@ -4677,7 +4677,7 @@ inline void compact_nodes(const document_data& d, std::size_t arena_size, std::v
         }
         out.push_back(r);
     };
-    emit(d.nodes);
+    copy_node(d.nodes);
     while (!stack.empty())
     {
         frame& top = stack.back();
@@ -4702,7 +4702,7 @@ inline void compact_nodes(const document_data& d, std::size_t arena_size, std::v
             v = document_data::deref(top.cur);
             top.cur = document_data::after(top.cur);
         }
-        emit(v); // may grow the stack (top is not used afterwards)
+        copy_node(v); // may grow the stack (top is not used afterwards)
     }
 }
 

tests/src/unit-json_view_image.cpp

@@ -294,7 +294,7 @@ TEST_CASE("json_view images: round trips")
     {
         // the hash is not seeded: keys can be found that land in one slot of
         // a table (see json_view: "colliding keys")
-        const auto keys_for = [](std::size_t slots, std::size_t colliding_count, std::size_t spread_count)
+        const auto keys_for = [](std::size_t table_size, std::size_t colliding_count, std::size_t spread_count)
         {
             std::vector<std::string> colliding;
             std::vector<std::string> spread;
@@ -306,7 +306,7 @@ TEST_CASE("json_view images: round trips")
                 {
                     key[i] = static_cast<char>('a' + (x % 26));
                 }
-                const bool lands_in_slot_zero = (nlohmann::detail::view::key_hash(key.data(), key.size()) & (slots - 1)) == 0;
+                const bool lands_in_slot_zero = (nlohmann::detail::view::key_hash(key.data(), key.size()) & (table_size - 1)) == 0;
                 if (lands_in_slot_zero && colliding.size() < colliding_count)
                 {
                     colliding.push_back(key);
@@ -335,14 +335,14 @@ TEST_CASE("json_view images: round trips")
         // long chain
         const struct // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays): an unnamed type
         {
-            std::size_t slots;
+            std::size_t table_size;
             std::size_t colliding;
             std::size_t spread;
         } cases[] = {{1024, 300, 0}, {512, 40, 160}};
         for (const auto& c : cases)
         {
-            CAPTURE(c.slots)
-            std::vector<std::string> keys = keys_for(c.slots, c.colliding, c.spread);
+            CAPTURE(c.table_size)
+            std::vector<std::string> keys = keys_for(c.table_size, c.colliding, c.spread);
             const std::size_t members = keys.size();
             // a duplicate of a colliding key, of the first and of a spread key
             const std::vector<std::string> duplicated = {keys[c.colliding - 1], keys[0], keys[members - 1]};