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◆ basic_json() [7/9]
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 = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<class InputIT , typename std::enable_if< std::is_same< InputIT, typename basic_json_t::iterator >::value or std::is_same< InputIT, typename basic_json_t::const_iterator >::value, int >::type = 0>
Constructs the JSON value with the contents of the range [first, last) . The semantics depends on the different types a JSON value can have:
- In case of a null type, invalid_iterator.206 is thrown.
- In case of other primitive types (number, boolean, or string), first must be
begin() and last must be end() . In this case, the value is copied. Otherwise, invalid_iterator.204 is thrown.
- In case of structured types (array, object), the constructor behaves as similar versions for
std::vector or std::map ; that is, a JSON array or object is constructed from the values in the range.
- Template Parameters
-
- Parameters
-
[in] | first | begin of the range to copy from (included) |
[in] | last | end of the range to copy from (excluded) |
- Precondition
- Iterators first and last must be initialized. This precondition is enforced with an assertion (see warning). If assertions are switched off, a violation of this precondition yields undefined behavior.
-
Range
[first, last) is valid. Usually, this precondition cannot be checked efficiently. Only certain edge cases are detected; see the description of the exceptions below. A violation of this precondition yields undefined behavior.
- Warning
- A precondition is enforced with a runtime assertion that will result in calling
std::abort if this precondition is not met. Assertions can be disabled by defining NDEBUG at compile time. See https://en.cppreference.com/w/cpp/error/assert for more information.
- Exceptions
-
invalid_iterator.201 | if iterators first and last are not compatible (i.e., do not belong to the same JSON value). In this case, the range [first, last) is undefined. |
invalid_iterator.204 | if iterators first and last belong to a primitive type (number, boolean, or string), but first does not point to the first element any more. In this case, the range [first, last) is undefined. See example code below. |
invalid_iterator.206 | if iterators first and last belong to a null value. In this case, the range [first, last) is undefined. |
- Complexity^^ Linear in distance between first and last.
- Exception safety^^ Strong guarantee: if an exception is thrown, there are no
- changes to any JSON value.
- Example^^ The example below shows several ways to create JSON values by
- specifying a subrange with iterators. ^^
2 #include <nlohmann/json.hpp> 9 json j_array = { "alpha", "bravo", "charly", "delta", "easy"}; 11 json j_object = {{ "one", "eins"}, { "two", "zwei"}}; 14 json j_array_range(j_array.begin() + 1, j_array.end() - 2); 15 json j_number_range(j_number.begin(), j_number.end()); 16 json j_object_range(j_object.begin(), j_object.find( "two")); 19 std::cout << j_array_range << '\n'; 20 std::cout << j_number_range << '\n'; 21 std::cout << j_object_range << '\n'; 26 json j_invalid(j_number.begin() + 1, j_number.end()); 30 std::cout << e.what() << '\n'; basic_json<> json default JSON class
detail::invalid_iterator invalid_iterator exception indicating errors with iterators
Output (play with this example online):^^ ["bravo","charly"]
42
{"one":"eins"}
[json.exception.invalid_iterator.204] iterators out of range
^^ The example code above can be translated withg++ -std=c++11 -Isingle_include doc/examples/basic_json__InputIt_InputIt.cpp -o basic_json__InputIt_InputIt
- Since
- version 1.0.0
Definition at line 14012 of file json.hpp.
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