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#define JSON_NO_IO

When defined, headers <cstdio>, <ios>, <iosfwd>, <istream>, and <ostream> are not included and parse functions relying on these headers are excluded. This is relevant for environments where these I/O functions are disallowed for security reasons (e.g., Intel Software Guard Extensions (SGX)).

Default definition

By default, JSON_NO_IO is not defined.

#undef JSON_NO_IO



The code below forces the library not to use the headers <cstdio>, <ios>, <iosfwd>, <istream>, and <ostream>.

#define JSON_NO_IO 1
#include <nlohmann/json.hpp>


Version history

  • Added in version 3.10.0.

Last update: May 17, 2022