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jsoncons::basic_json::is

template <typename T,typename... Args>
bool is(Args&&... args) const noexcept; (1)

bool is_null() const noexcept; (2)

bool is_string() const noexcept; (3)

bool is_int64() const noexcept; (4)

bool is_uint64() const noexcept; (5)

bool is_double() const noexcept; (6)

bool is_number() const noexcept; (7)

bool is_bool() const noexcept; (8)

bool is_byte_string() const; (9)

bool is_bignum() const; (10)

bool is_array() const noexcept; (11)

bool is_object() const noexcept; (12)

(1) Generic is equivalent to type T. Returns true if the json value is the same as type T according to json_type_traits, false otherwise.

bool is<X<T>> const noexcept

If the type X is not std::basic_string but otherwise satisfies SequenceContainer, is<X<T>>() returns true if the json value is an array and each element is the "same as" type T according to json_type_traits, false otherwise. bool is<Xstd::string,T> const noexcept If the type 'X' satisfies AssociativeContainer or UnorderedAssociativeContainer, is<X<T>>() returns true if the json value is an object and each mapped value is the "same as" T according to json_type_traits, false otherwise.

(2) Same as is<jsoncons::null_type>().
Returns true if the json value is null, false otherwise.

(3) Same as is<std::string>().
Returns true if the json value is of string type, false otherwise.

(4) Same as is<int64_t>().
Returns true if the json value is integral and within the range of int64_t, false otherwise.

(5) Same as is<uint64_t>().
Returns true if the json value is integral and within the range of uint64_t, false otherwise.

(6) Same as is<double>().
Returns true if the json value is floating point and within the range of double, false otherwise.

(7) Same as is<int64_t>() || is<uint64_t>() || is<double>().

(8) Same as is<bool>().
Returns true if the json value is of boolean type, false otherwise.

(10) Same as is<jsoncons::bigint>().
Returns true if is<int64_t>() || is<uint64_t>() is true, or if isstd::string()istrueand the string holds an integer value, otherwisefalse`.

(11) Returns true if the json value is an array, false otherwise.

(12) Returns true if the json value is an object, false otherwise.

Examples

json j = json::parse(R"(
{
    "k1" : 2147483647,
    "k2" : 2147483648,
    "k3" : -10,
    "k4" : 10.5,
    "k5" : true,
    "k6" : "10.5"
}
)");

std::cout << std::boolalpha << "(1) " << j["k1"].is<int32_t>() << '\n';
std::cout << std::boolalpha << "(2) " << j["k2"].is<int32_t>() << '\n';
std::cout << std::boolalpha << "(3) " << j["k2"].is<long long>() << '\n';
std::cout << std::boolalpha << "(4) " << j["k3"].is<signed char>() << '\n';
std::cout << std::boolalpha << "(5) " << j["k3"].is<uint32_t>() << '\n';
std::cout << std::boolalpha << "(6) " << j["k4"].is<int32_t>() << '\n';
std::cout << std::boolalpha << "(7) " << j["k4"].is<double>() << '\n';
std::cout << std::boolalpha << "(8) " << j["k5"].is<int>() << '\n';
std::cout << std::boolalpha << "(9) " << j["k5"].is<bool>() << '\n';
std::cout << std::boolalpha << "(10) " << j["k6"].is<double>() << '\n';

Output:

(1) true
(2) false
(3) true
(4) true
(5) false
(6) false
(7) true
(8) false
(9) true
(10) false