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[question] how to get a string value by pointer #683
Description
I wrapped a C lib for using json.hpp, like this:
json_string = {"file":"/opt/test.conf"}
set json_string to a static json object
static json para = json::parse(json_string);
`
extern "C" const char*
get_json_string()
{
if (para["file"].is_string())
{
return para["file"].get<std::string>().c_str();
}
}
`
but actually, get_json_string cannot get the real address of para, so how to get a string value in this way ?
I don't want to use strcpy like this:
`
get_json_string(char* value)
{
if (para["file"].is_string())
{
strcpy(value, para["file"].get<std::string>().c_str());
}
}
`
Activity
zhishupp commentedon Aug 9, 2017
I find a way like this:
`
extern "C" const char*
get_json_string()
{
if (para["file"].is_string())
{
}
}
`
now I can get the correct data, is that right ?
and
get<json::string_t*>()->c_str(); or get_ptr<json::string_t*>()->c_str();which one is corret, or better ?
nlohmann commentedon Aug 9, 2017
You should use
get_ptrto be sure no copies are made:nlohmann commentedon Aug 10, 2017
Does this solve the issue?
zhishupp commentedon Aug 10, 2017
many thanks, issue has been solved ^^