2025-01-12 20:40:48 +08:00

903 lines
19 KiB
C++

//
// Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Official repository: https://github.com/boostorg/json
//
#ifdef _MSC_VER
# pragma warning(push)
# pragma warning(disable: 4101)
# pragma warning(disable: 4996)
#elif defined(__clang__)
# pragma clang diagnostic push
# pragma clang diagnostic ignored "-Wunused"
# pragma clang diagnostic ignored "-Wmismatched-tags"
#elif defined(__GNUC__)
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wunused"
#endif
#include <boost/json.hpp>
#include <algorithm>
#include <cmath>
#include <map>
#include <numeric>
#include <string>
#include <vector>
#include "test_suite.hpp"
#include "doc_types.hpp"
//[snippet_conv_spec_trait2
namespace boost
{
namespace json
{
template<>
struct is_sequence_like< user_ns::ip_address >
: std::false_type
{ };
} // namespace json
} // namespace boost
//]
namespace user_ns2 {
class ip_address : public user_ns::ip_address
{
public:
using user_ns::ip_address::ip_address;
};
using namespace boost::json;
//[snippet_tag_invoke_1
void
tag_invoke( const value_from_tag&, value& jv, ip_address const& addr )
{
// Store the IP address as a 4-element array of octets
const unsigned char* b = addr.begin();
jv = { b[0], b[1], b[2], b[3] };
}
ip_address
tag_invoke( const value_to_tag< ip_address >&, value const& jv )
{
array const& arr = jv.as_array();
return ip_address(
arr.at(0).to_number< unsigned char >(),
arr.at(1).to_number< unsigned char >(),
arr.at(2).to_number< unsigned char >(),
arr.at(3).to_number< unsigned char >() );
}
//]
//[snippet_nothrow_1
result_for< ip_address, value >::type
tag_invoke( const try_value_to_tag< ip_address >&, value const& jv )
{
if( !jv.is_array() )
return make_error_code( std::errc::invalid_argument );
array const& arr = jv.get_array();
if( arr.size() != 4 )
return make_error_code( std::errc::invalid_argument );
result< unsigned char > oct1 = try_value_to< unsigned char >( arr[0] );
if( !oct1 )
return make_error_code( std::errc::invalid_argument );
result< unsigned char > oct2 = try_value_to< unsigned char >( arr[1] );
if( !oct2 )
return make_error_code( std::errc::invalid_argument );
result< unsigned char > oct3 = try_value_to< unsigned char >( arr[2] );
if( !oct3 )
return make_error_code( std::errc::invalid_argument );
result< unsigned char > oct4 = try_value_to< unsigned char >( arr[3] );
if( !oct4 )
return make_error_code( std::errc::invalid_argument );
return ip_address{ *oct1, *oct2, *oct3, *oct4 };
}
//]
} // namespace user_ns
namespace boost {
namespace json {
namespace {
//[snippet_strings_5
string greeting( string_view first_name, string_view last_name )
{
const char hello[] = "Hello, ";
const std::size_t sz = first_name.size() + last_name.size() + sizeof(hello) + 1;
string js;
js.reserve(sz);
char* p = std::copy( hello, hello + sizeof(hello) - 1, js.data() );
p = std::copy( first_name.begin(), first_name.end(), p );
*p++ = ' ';
p = std::copy( last_name.begin(), last_name.end(), p );
*p++ = '!';
js.grow( sz );
return js;
}
//]
void
usingStrings()
{
{
//[snippet_strings_1
string str1; // empty string, uses the default memory resource
string str2( make_shared_resource<monotonic_resource>() ); // empty string, uses a counted monotonic resource
//]
}
{
//[snippet_strings_2
std::string sstr1 = "helloworld";
std::string sstr2 = "world";
json::string jstr1 = "helloworld";
json::string jstr2 = "world";
assert( jstr2.insert(0, jstr1.subview(0, 5)) == "helloworld" );
// this is equivalent to
assert( sstr2.insert(0, sstr1, 0, 5) == "helloworld" );
//]
}
{
//[snippet_strings_3
std::string sstr = "hello";
json::string jstr = "hello";
assert(sstr.append({'w', 'o', 'r', 'l', 'd'}) == "helloworld");
// such syntax is inefficient, and the same can
// be achieved with a character array.
assert(jstr.append("world") == "helloworld");
//]
}
{
//[snippet_strings_4
json::string str = "Boost.JSON";
json::string_view sv = str;
// all of these call compare(string_view)
str.compare(sv);
str.compare(sv.substr(0, 5));
str.compare(str);
str.compare("Boost");
//]
}
{
auto str = greeting( "John", "Smith" );
(void)str;
assert( str == "Hello, John Smith!");
}
}
//----------------------------------------------------------
void
usingValues()
{
{
//[snippet_value_1
value jv1;
value jv2( nullptr );
assert( jv1.is_null() );
assert( jv2.is_null() );
//]
}
{
//[snippet_value_2
value jv( object_kind );
assert( jv.kind() == kind::object );
assert( jv.is_object() );
assert( ! jv.is_number() );
//]
}
{
auto f = []{
//[snippet_value_3
value jv( object_kind );
if( auto p = jv.if_object() )
return p->size();
//]
return std::size_t(0);
};
(void)f;
}
{
//[snippet_value_4
value jv;
jv = value( array_kind );
assert( jv.is_array() );
jv.emplace_string();
assert( jv.is_string() );
//]
}
{
//[snippet_value_5
value jv;
jv.emplace_string() = "Hello, world!";
int64_t& num = jv.emplace_int64();
num = 1;
assert( jv.is_int64() );
//]
}
{
try
{
//[snippet_value_6
value jv( true );
jv.as_bool() = true;
jv.as_string() = "Hello, world!"; // throws an exception
//]
}
catch(...)
{
}
}
{
//[snippet_value_7
value jv( string_kind );
if( string* str = jv.if_string() )
*str = "Hello, world!";
//]
}
{
//[snippet_value_8
value jv( string_kind );
// The compiler's static analysis can see that
// a null pointer is never dereferenced.
*jv.if_string() = "Hello, world!";
//]
}
}
//----------------------------------------------------------
void
usingInitLists()
{
{
//[snippet_init_list_1
value jv = {
{ "name", "John Doe" },
{ "active", true },
{ "associated-accounts", nullptr },
{ "total-balance", 330.00 },
{ "account-balances", { 84, 120, 126 } } };
//]
}
{
//[snippet_init_list_2
value jv = { true, 2, "hello", nullptr };
assert( jv.is_array() );
assert( jv.as_array().size() == 4 );
assert( serialize(jv) == R"([true,2,"hello",null])" );
//]
}
{
//[snippet_init_list_3
value jv = { true, 2, "hello", { "bye", nullptr, false } };
assert( jv.is_array() );
assert( jv.as_array().back().is_array() );
assert( serialize(jv) == R"([true,2,"hello",["bye",null,false]])" );
//]
}
{
//[snippet_init_list_4
// Should this be an array or an object?
value jv = { { "hello", 42 }, { "world", 43 } };
//]
}
{
//[snippet_init_list_5
value jv1 = { { "hello", 42 }, { "world", 43 } };
assert( jv1.is_object() );
assert( jv1.as_object().size() == 2 );
assert( serialize(jv1) == R"({"hello":42,"world":43})" );
// All of the following are arrays
value jv2 = { { "make", "Tesla" }, { "model", 3 }, "black" };
value jv3 = { { "library", "JSON" }, { "Boost", "C++", "Fast", "JSON" } };
value jv4 = { { "color", "blue" }, { 1, "red" } };
assert( jv2.is_array() && jv3.is_array() && jv4.is_array() );
//]
}
{
//[snippet_init_list_6
value jv = { { "hello", 42 }, array{ "world", 43 } };
assert( jv.is_array() );
array& ja = jv.as_array();
assert( ja[0].is_array() && ja[1].is_array());
assert ( serialize(jv) == R"([["hello",42],["world",43]])" );
//]
(void)ja;
}
{
//[snippet_init_list_7
value jv = { { "mercury", 36 }, { "venus", 67 }, { "earth", 93 } };
assert( jv.is_object() );
assert( serialize(jv) == R"({"mercury":36,"venus":67,"earth":93})" );
array ja = { { "mercury", 36 }, { "venus", 67 }, { "earth", 93 } };
assert( serialize(ja) == R"([["mercury",36],["venus",67],["earth",93]])" );
//]
(void)ja;
}
{
//[snippet_init_list_8
object jo = { { "mercury", { { "distance", 36 } } }, { "venus", { 67, "million miles" } }, { "earth", 93 } };
assert( jo["mercury"].is_object() );
assert( jo["venus"].is_array() );
//]
}
{
//[snippet_init_list_9
object jo1 = { { "john", 100 }, { "dave", 500 }, { "joe", 300 } };
value jv = { { "clients", std::move(jo1) } };
object& jo2 = jv.as_object()["clients"].as_object();
assert( ! jo2.empty() && jo1.empty() );
assert( serialize(jv) == R"({"clients":{"john":100,"dave":500,"joe":300}})" );
//]
(void)jo2;
}
}
//----------------------------------------------------------
void
usingArrays()
{
{
//[snippet_arrays_1
array arr1; // empty array, uses the default memory resource
array arr2( make_shared_resource<monotonic_resource>() ); // empty array, uses a counted monotonic resource
//]
}
{
//[snippet_arrays_2
array arr( { "Hello", 42, true } );
//]
}
try
{
//[snippet_arrays_3
array arr;
arr.emplace_back( "Hello" );
arr.emplace_back( 42 );
arr.emplace_back( true );
//]
//[snippet_arrays_4
assert( arr[0].as_string() == "Hello" );
// The following line throws std::out_of_range, since the index is out of range
arr.at( 3 ) = nullptr;
//]
}
catch (...)
{
}
}
//----------------------------------------------------------
void
usingObjects()
{
{
//[snippet_objects_1
object obj1; // empty object, uses the default memory resource
object obj2( make_shared_resource<monotonic_resource>() ); // empty object, uses a counted monotonic resource
//]
}
{
//[snippet_objects_2
object obj( {{"key1", "value1" }, { "key2", 42 }, { "key3", false }} );
//]
}
{
//[snippet_objects_3
object obj;
obj.emplace( "key1", "value1" );
obj.emplace( "key2", 42 );
obj.emplace( "key3", false );
//]
}
try
{
//[snippet_objects_4
object obj;
obj["key1"] = "value1";
obj["key2"] = 42;
obj["key3"] = false;
// The following line throws std::out_of_range, since the key does not exist
obj.at( "key4" );
//]
}
catch (...)
{
}
{
//[snippet_objects_5
object obj{{"arr", {1, 11}}};
value& arr = obj.at("arr");
obj.emplace("added", "value"); // invalidates arr
//]
(void)arr;
}
}
//[snippet_conv_5
template< class T >
struct vec3
{
T x, y, z;
};
template< class T >
void tag_invoke( const value_from_tag&, value& jv, const vec3<T>& vec )
{
jv = {
{ "x", vec.x },
{ "y", vec.y },
{ "z", vec.z }
};
}
//]
//[snippet_conv_10
struct customer
{
std::uint64_t id;
std::string name;
bool late;
customer() = default;
customer( std::uint64_t i, const std::string& n, bool l )
: id( i ), name( n ), late( l ) { }
};
void tag_invoke( const value_from_tag&, value& jv, customer const& c )
{
// Assign a JSON value
jv = {
{ "id", c.id },
{ "name", c.name },
{ "late", c.late }
};
}
//]
//[snippet_conv_14
customer tag_invoke( const value_to_tag<customer>&, const value& jv )
{
// at() throws if `jv` is not an object, or if the key is not found.
// as_uint64() will throw if the value is not an unsigned 64-bit integer.
std::uint64_t id = jv.at( "id" ).as_uint64();
// We already know that jv is an object from
// the previous call to jv.as_object() succeeding,
// now we use jv.get_object() which skips the
// check. value_to will throw if jv.kind() != kind::string
std::string name = value_to< std::string >( jv.get_object().at( "name" ) );
// id and name are constructed from JSON in the member
// initializer list above, but we can also use regular
// assignments in the body of the function as shown below.
// as_bool() will throw if kv.kind() != kind::bool
bool late = jv.get_object().at( "late" ).as_bool();
return customer(id, name, late);
}
//]
void
usingExchange()
{
{
//[snippet_conv_1
std::vector< int > v1{ 1, 2, 3, 4 };
// Convert the vector to a JSON array
value jv = value_from( v1 );
assert( serialize( jv ) == R"([1,2,3,4])" );
// Convert back to vector< int >
std::vector< int > v2 = value_to< std::vector< int > >( jv );
assert( v1 == v2 );
//]
(void)v2;
}
{
using namespace user_ns2;
//[snippet_tag_invoke_3
std::map< std::string, ip_address > computers = {
{ "Alex", { 192, 168, 1, 1 } },
{ "Blake", { 192, 168, 1, 2 } },
{ "Carol", { 192, 168, 1, 3 } },
};
// conversions are applied recursively;
// the key type and value type will be converted
// using value_from as well
value jv = value_from( computers );
assert( jv.is_object() );
value serialized = parse(R"(
{
"Alex": [ 192, 168, 1, 1 ],
"Blake": [ 192, 168, 1, 2 ],
"Carol": [ 192, 168, 1, 3 ]
}
)");
assert( jv == serialized );
//]
(void)jv;
}
{
using namespace user_ns2;
//[snippet_tag_invoke_2
ip_address addr = { 127, 0, 0, 12 };
value jv = value_from( addr );
assert( serialize( jv ) == R"([127,0,0,12])" );
// Convert back to IP address
ip_address addr2 = value_to< ip_address >( jv );
assert(std::equal(
addr.begin(), addr.end(), addr2.begin() ));
//]
(void)addr2;
}
{
using namespace user_ns2;
//[snippet_nothrow_2
value jv = parse( R"([127,0,0,12])" );
result< ip_address > addr = try_value_to< ip_address >( jv );
assert( addr.has_value() );
ip_address addr2{ 127, 0, 0, 12 };
assert(std::equal(
addr->begin(), addr->end(), addr2.begin() ));
// this fails without exception
addr = try_value_to< ip_address >( value() );
assert( addr.has_error() );
//]
(void)addr;
(void)addr2;
}
{
//[snippet_conv_recursive
std::map< std::string, std::pair<int, bool> > m = {
{"a", {1, false}},
{"b", {4, true}},
{"c", {5, false}},
};
value jv = value_from( m );
assert(( jv == object{
{"a", array{1, false}},
{"b", array{4, true}},
{"c", array{5, false}},
}));
//]
}
}
void
usingPointer()
{
//[snippet_pointer_1
value jv = { {"one", 1}, {"two", 2} };
assert( jv.at("one") == jv.at_pointer("/one") );
jv.at_pointer("/one") = {{"foo", "bar"}};
assert( jv.at("one").at("foo") == jv.at_pointer("/one/foo") );
jv.at_pointer("/one/foo") = {true, 4, "qwerty"};
assert( jv.at("one").at("foo").at(1) == jv.at_pointer("/one/foo/1") );
//]
value* elem1 = [&]() -> value*
{
//[snippet_pointer_2
object* obj = jv.if_object();
if( !obj )
return nullptr;
value* val = obj->if_contains("one");
if( !val )
return nullptr;
obj = val->if_object();
if( !obj )
return nullptr;
val = obj->if_contains("foo");
if( !val )
return nullptr;
array* arr = val->if_array();
if( !arr )
return nullptr;
return arr->if_contains(1);
//]
}();
value* elem2 = [&]() -> value*
{
//[snippet_pointer_3
error_code ec;
return jv.find_pointer("/one/foo/1", ec);
//]
}();
(void)elem1;
(void)elem2;
assert( elem1 == elem2 );
}
void
usingSetAtPointer()
{
//[snippet_pointer_4
value jv;
jv.set_at_pointer("/two/bar/0", 12);
assert( jv.is_object() );
assert( jv.at_pointer("/two").is_object() );
assert( jv.at_pointer("/two/bar").is_array() );
assert( jv.at_pointer("/two/bar/0") == 12 );
//]
jv = nullptr;
//[snippet_pointer_5
set_pointer_options opts;
opts.create_arrays = false;
jv.set_at_pointer("/two/bar/0", 12, opts);
assert( jv.is_object() );
assert( jv.at_pointer("/two").is_object() );
assert( jv.at_pointer("/two/bar").is_object() ); // object, not array
assert( jv.at_pointer("/two/bar/0") == 12 );
//]
}
BOOST_STATIC_ASSERT(
has_value_from<customer>::value);
BOOST_STATIC_ASSERT(
has_value_from<user_ns2::ip_address>::value);
BOOST_STATIC_ASSERT(
has_value_to<user_ns2::ip_address>::value);
} // (anon)
} // json
} // boost
//----------------------------------------------------------
namespace {
class my_non_deallocating_resource { };
} // (anon)
//[snippet_allocators_14
namespace boost {
namespace json {
template<>
struct is_deallocate_trivial< my_non_deallocating_resource >
{
static constexpr bool value = true;
};
} // json
} // boost
//]
namespace boost {
namespace json {
namespace
{
void
usingSpecializedTrait()
{
value jv1{127, 0, 0, 1};
auto const addr = value_to< user_ns::ip_address >( jv1 );
auto const jv2 = value_from(addr);
assert( jv1 == jv2 );
}
} // namespace
class snippets_test
{
public:
void
run()
{
usingValues();
usingInitLists();
usingExchange();
usingArrays();
usingObjects();
usingStrings();
usingPointer();
usingSpecializedTrait();
usingSetAtPointer();
BOOST_TEST_PASS();
}
};
TEST_SUITE(snippets_test, "boost.json.snippets");
} // namespace json
} // namespace boost