Weird serialization issue with strings that are file paths about toml11

[ToruNiina]

It is a valid multi-line string and is equivalent to the value you expected. (cf. https://toml.io/en/v1.0.0#string)
The default toml11 serializer uses multi-line version if the length exceeds the maximum width (the threshold is a bit fuzzy, though).

You can change max width by

const std::string configString = toml::format(data, 200);

And then it works as you expected.

By the way, TOML has another form of string called literal string (also explained in https://toml.io/en/v1.0.0#string) that is suitable for the case where many backslashes exist. You can use literal string by passing an enum class string_t to toml::string constructor.

const toml::value data{ { {"exePath", toml::string(sExePath, toml::string_t::literal)} } };

Then you will get the following.

exePath = 'C:\Users\ifexception\source\repos\Toml11FilePathsMre\x64\Debug\Toml11FilePathsMre.exe'