JSON for Modern C++  3.0
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = int64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator>
using nlohmann::basic_json::parser_callback_t = std::function<bool(int depth, parse_event_t event, const basic_json& parsed)>
Parameters
depthfoo