Description

Throwing an exception in serializer function after the output json object is already initialized results in a memory leak (detected with both ASan and valgrind):

void adl_serializer<Foo>::to_json(json& j, Foo const& f) {
    j["a"] = 42;
    throw std::runtime_error("error");
}

Reproduction steps

Reproducer here: https://godbolt.org/z/dvorMExWh

Expected vs. actual results

Expected: no memory leak

Minimal code example

No response

Error messages

No response

Compiler and operating system

linux, clang 15, gcc 12.2

Library version

3.11.2, godbolt trunk, 7f72eed

Validation

• The bug also occurs if the latest version from the develop branch is used.
• I can successfully compile and run the unit tests.