Floating point value loses decimal point during dump

[kishorenc]

Bug Report

Let's say I've a floating point value "4.0". When it's dumped to disk using .dump() it's being written as just "4". So, the type of the value goes from float to int when I read the data back using parse().

• Please describe the steps to reproduce the issue. Can you provide a small but working code example?

std::string json_str = "{\"average_rating\": 4.0 }";
nlohmann::json document = nlohmann::json::parse(json_str);
std::cout << "Float? " << document["average_rating"].is_number_float() << std::endl;
std::string json_serialized = document.dump();
std::cout << "json_serialized: " << json_serialized << std::endl;
document = nlohmann::json::parse(json_serialized);
std::cout << "Float? " << document["average_rating"].is_number_float() << std::endl;

The output:

Float? 1
json_serialized: {"average_rating":4}
Float? 0

• What is the expected behavior?

The .dump() should not drop the trailing ".0".

• And what is the actual behavior instead?

The .dump() drops the trailing .0.

• Which compiler and operating system are you using? Is it a supported compiler?

Apple LLVM version 7.3.0 (clang-703.0.31)

• Did you use a released version of the library or the version from the develop branch?

Release version.

[kishorenc]

Sorry, this has been fixed in a later release via: #378