json-parser

Though we include Boost JSON as a dependency for benchmarking purposes, we do not include it as part of our benchmarks currently.

Hey folks, thanks for a pretty bad ass library! I'm seeing a 3-3.3x gain when decoding fairly large JSON payloads (40-50MB) as compared stdlib/json-iterator.

Few things in the generated code that struck me as odd are the allocation sizes for slices/maps:

• Slice is set to size 1 initially, values are appended using append
• Map does not have a default size specified

Instead of this, I