This library contains class to represent JSON object and functions to import/export it.
This library is header-only (no precompiled files) and single-file (only one file for everything).
All contents are kept in namespace tokox::json as listed below.
It does not use any external libraries (only standard C++ libraries).
Test program called test.cpp is just reading and writing same one JSON object.
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Class
objectrepresents JSON object. It is made on top ofstd::any -
value_typeis an enum representing JSON objects types -
Types are represented as following:
JSON type C++ type value_typeNull[None] (std::any has no value) NullBooleanboolBoolNumberlong long intandlong doubleIntorFloatStringstd::stringStringArraystd::vector<object>VectorObjectstd::map<std::string, object>Map -
import_erroris an exception class thrown by import functions (export functions don't throw (see below)) -
ERR_???are error messages -
float_precis float precision
| Function | Description |
|---|---|
object from(iterator& input_iterator, iterator input_end) |
Main function for import. Detects what type of object it is and calls corresponding TYPE_from function. Takes iterator to current input character and input end (it may be iterator to std::*stream, std::string, std::vector, c-string - basically whatever you want). iterator is a template parameter. Returns object with imported JSON |
object TYPE_from(iterator& input_iterator, iterator input_end) |
Imports specific type TYPE (for every JSON type). They are called by from after type detection. They import specific type - if it isn't correct they throw import_error |
object from(std::string& input_string) |
Returns from(input_string->iterator) (first) |
object& from(object& obj, std::string& input_string) |
Calls from(input_string) (above), saves result to obj and returns it |
object from(std::istream& input_stream) |
Returns from(input_stream->iterator) (first) |
object& from(object& obj, std::istream& input_stream) |
Calls from(input_stream) (above), saves result to obj and returns it |
std::istream& operator>>(std::istream& input_stream, object& obj) |
Calls from(obj, input_stream) (above) and returns input_stream |
number_from is returning object containing Int (long long int) or Float (long double). It chooses the better option. Here is how it works:
| Condition for number | value_type (C++ type) |
|---|---|
doesn't fit in long long int (less than one or more than std::numeric_limits<long long int>::max()) |
Float (long double) |
fits in long long int and is an integer |
Int (long long int) |
fits in long long int and long double loses precision (is less precise than rounded long long int) |
Int (long long int) |
Well, long long int isn't any better than long double there! (Other) |
Float (long double) |
You can always cast it to another after import.
| Function | Description |
|---|---|
iterator& to(object& obj, iterator& output_iterator, int tab = -1) |
Main function for export. Checks what type of object it is and calls corresponding TYPE_to function. Takes JSON object, iterator to current output character and optional argument tab used for indentation (recursive objects). Negative tab means no indentation. iterator is a template parameter. Returns output_iterator |
iterator& TYPE_to(object& obj, iterator& output_iterator, int tab = -1) |
Exports specific type TYPE (for every JSON type). They are called by to after type check. They export specific type - if it isn't correct std::get (std::variant) in object::get_value will throw std::bad_variant_access |
std::string& to(object& obj, std::string& output_string, int tab = -1) |
Calls to(obj, output_string->iterator, tab) (first) and returns output_string |
std::string to(object& obj, int tab = -1) |
Creates an instance of std::string and calls to(obj, created_string, tab) (above) and returns created_string |
std::ostream& to(object& obj, std::ostream& output_stream, int tab = -1) |
Calls to(obj, output_stream->iterator, tab) (first), returns output_stream |
std::ostream& operator<<(std::ostream& output_stream, object& obj) |
Returns to(obj, output_stream) (above) |
This library is licensed under the terms of the MIT license. Why did I put this here? I'm sure no one will care or even read this