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### jsoncons::encode_json, jsoncons::encode_json_pretty, jsoncons::try_encode_json, jsoncons::try_encode_json_pretty
Encode a C++ data structure to a JSON formatted string or stream. `encode_json` will work for all types that
have json reflection traites defined.
```cpp
#include <jsoncons/encode_json.hpp>
template <typename T,typename CharT> (1)
void encode_json(const T& val, basic_json_visitor<CharT>& encoder);
template <typename T,typename CharContainer>
void encode_json(const T& val, CharContainer& cont,
const basic_json_encode_options<CharContainer::value_type>& options (2)
= basic_json_encode_options<CharContainer::value_type>();
template <typename T,typename CharT>
void encode_json(const T& val, std::basic_ostream<CharT>& os,
const basic_json_encode_options<CharT>& options (3)
= basic_json_encode_options<CharT>();
template <typename T,typename CharContainer,typename Alloc,typename TempAlloc>
void encode_json(const allocator_set<Alloc,TempAlloc>& aset,
const T& val, CharContainer& cont,
const basic_json_encode_options<CharContainer::value_type>& options (4) (since 0.171.0)
= basic_json_encode_options<CharContainer::value_type>();
template <typename T,typename CharT,typename Alloc,typename TempAlloc>
void encode_json(const allocator_set<Alloc,TempAlloc>& aset,
const T& val, std::basic_ostream<CharT>& os,
const basic_json_encode_options<CharT>& options (5) (since 0.171.0)
= basic_json_encode_options<CharT>());
template <typename T,typename CharContainer>
void encode_json_pretty(const T& val, CharContainer& cont,
const basic_json_encode_options<CharContainer::value_type>& options (6) (since 0.155.0)
= basic_json_encode_options<CharContainer::value_type>());
template <typename T,typename CharT>
void encode_json_pretty(const T& val, std::basic_ostream<CharT>& os,
const basic_json_encode_options<CharT>& options (7) (since 0.155.0)
= basic_json_encode_options<CharT>());
template <typename T,typename CharContainer>
void encode_json_pretty(const allocator_set<Alloc,TempAlloc>& aset,
const T& val, CharContainer& cont,
const basic_json_encode_options<CharContainer::value_type>& options (8) (since 1.4.0)
= basic_json_encode_options<CharContainer::value_type>());
template <typename T,typename CharT>
void encode_json_pretty(const allocator_set<Alloc,TempAlloc>& aset,
const T& val, std::basic_ostream<CharT>& os,
const basic_json_encode_options<CharT>& options (9) (since 1.4.0)
template <typename T,typename CharT>
write_result try_encode_json(const T& val, basic_json_visitor<CharT>& encoder); (10) (since 1.4.0)
= basic_json_encode_options<CharT>());
template <typename T,typename CharContainer>
write_result try_encode_json(const T& val, CharContainer& cont,
const basic_json_encode_options<CharContainer::value_type>& options (11) (since 1.4.0)
= basic_json_encode_options<CharContainer::value_type>();
template <typename T,typename CharT>
write_result try_encode_json(const T& val, std::basic_ostream<CharT>& os,
const basic_json_encode_options<CharT>& options (12) (since 1.4.0)
= basic_json_encode_options<CharT>();
template <typename T,typename CharContainer,typename Alloc,typename TempAlloc>
write_result try_encode_json(const allocator_set<Alloc,TempAlloc>& aset,
const T& val, CharContainer& cont,
const basic_json_encode_options<CharContainer::value_type>& options (13) (since 1.4.0)
= basic_json_encode_options<CharContainer::value_type>();
template <typename T,typename CharT,typename Alloc,typename TempAlloc>
write_result try_encode_json(const allocator_set<Alloc,TempAlloc>& aset,
const T& val, std::basic_ostream<CharT>& os,
const basic_json_encode_options<CharT>& options (14) (since 1.4.0)
= basic_json_encode_options<CharT>());
template <typename T,typename CharContainer>
write_result try_encode_json_pretty(const T& val, CharContainer& cont,
const basic_json_encode_options<CharContainer::value_type>& options (15) (since 1.4.0)
= basic_json_encode_options<CharContainer::value_type>());
template <typename T,typename CharT>
write_result try_encode_json_pretty(const T& val, std::basic_ostream<CharT>& os,
const basic_json_encode_options<CharT>& options (16) (since 1.4.0)
= basic_json_encode_options<CharT>());
template <typename T,typename CharContainer>
write_result try_encode_json_pretty(const allocator_set<Alloc,TempAlloc>& aset,
const T& val, CharContainer& cont,
const basic_json_encode_options<CharContainer::value_type>& options (17) (since 1.4.0)
= basic_json_encode_options<CharContainer::value_type>());
template <typename T,typename CharT>
write_result try_encode_json_pretty(const allocator_set<Alloc,TempAlloc>& aset,
const T& val, std::basic_ostream<CharT>& os,
const basic_json_encode_options<CharT>& options (18) (since 1.4.0)
= basic_json_encode_options<CharT>());
```
(1) Write val to an encoder
(2) Encode `val` to a character container with "minified" output (single line) using the specified (or defaulted) [options](basic_json_options.md).
(3) Encode `val` to an output stream in "minified" output using the specified (or defaulted) [options](basic_json_options.md).
Functions (4)-(5) are identical to (2)-(3) except an [allocator_set](allocator_set.md) is passed as an additional argument.
(6) Encode `val` to a character container with "prettified" output (line indentation) using the specified (or defaulted) [options](basic_json_options.md).
(7) Encode `val` to an output stream with "prettified" output using the specified (or defaulted) [options](basic_json_options.md).
Functions (8)-(9) are identical to (6)-(7) except an [allocator_set](allocator_set.md) is passed as an additional argument.
(10)-(18) Non-throwing versions of (1)-(9)
#### Parameters
<table>
<tr>
<td>aset</td>
<td>[allocator_set](allocator_set.md)</td>
</tr>
<tr>
<td>val</td>
<td>C++ data structure</td>
</tr>
<tr>
<td>visitor</td>
<td>JSON output visitor</td>
</tr>
<tr>
<td>options</td>
<td>Serialization options</td>
</tr>
<tr>
<td>os</td>
<td>Output stream</td>
</tr>
</table>
#### Return value
(1)-(9) None
(10)-(18) [write_result](write_result.md)
#### Exceptions
(1)-(9) Throw [ser_error](ser_error.md) if encode fails.
Any overload may throw `std::bad_alloc` if memory allocation fails.
### Examples
#### Map with string-tuple pairs
```cpp
#include <iostream>
#include <map>
#include <tuple>
#include <jsoncons/json.hpp>
using namespace jsoncons;
int main()
{
using employee_collection = std::map<std::string,std::tuple<std::string,std::string,double>>;
employee_collection employees =
{
{"John Smith",{"Hourly","Software Engineer",10000}},
{"Jane Doe",{"Commission","Sales",20000}}
};
std::cout << "(1)\n" << '\n';
encode_json(employees,std::cout);
std::cout << "\n\n";
std::cout << "(2) Again, with pretty print\n" << '\n';
encode_json_pretty(employees, std::cout);
}
```
Output:
```
(1)
{"Jane Doe":["Commission","Sales",20000.0],"John Smith":["Hourly","Software Engineer",10000.0]}
(2) Again, with pretty print
{
"Jane Doe": ["Commission","Sales",20000.0],
"John Smith": ["Hourly","Software Engineer",10000.0]
}
```
#### Contain JSON output in an object (prettified output)
```cpp
#include <iostream>
#include <map>
#include <tuple>
#include <jsoncons/json.hpp>
using namespace jsoncons;
int main()
{
std::map<std::string, std::tuple<std::string, std::string, double>> employees =
{
{"John Smith",{"Hourly","Software Engineer",10000}},
{"Jane Doe",{"Commission","Sales",20000}}
};
json_stream_encoder encoder(std::cout);
encoder.begin_object();
encoder.key("Employees");
encode_json(employees, encoder);
encoder.end_object();
encoder.flush();
}
```
Output:
```json
{
"Employees": {
"Jane Doe": ["Commission","Sales",20000.0],
"John Smith": ["Hourly","Software Engineer",10000.0]
}
}
```
#### Contain JSON output in an object (compressed output)
```cpp
#include <iostream>
#include <map>
#include <tuple>
#include <jsoncons/json.hpp>
using namespace jsoncons;
int main()
{
std::map<std::string, std::tuple<std::string, std::string, double>> employees =
{
{"John Smith",{"Hourly","Software Engineer",10000}},
{"Jane Doe",{"Commission","Sales",20000}}
};
compact_json_stream_encoder encoder(std::cout);
encoder.begin_object();
encoder.key("Employees");
encode_json(employees, encoder);
encoder.end_object();
encoder.flush();
}
```
Output:
```json
{"Employees":{"Jane Doe":["Commission","Sales",20000.0],"John Smith":["Hourly","Software Engineer",10000.0]}}
```
### See also
[basic_json_visitor](basic_json_visitor.md)
[basic_json_options](basic_json_options.md)
[basic_json_encoder](basic_json_encoder.md)
[decode_json](decode_json.md)
|
