SSL_CTRL_GET_TLS_EXT_HEARTBEAT_PENDING

Undocumented in source but is binding to C. You might be able to learn more by searching the web for its name.
version(!OPENSSL_NO_TLSEXT && !OPENSSL_NO_HEARTBEATS)
extern (C) nothrow
enum SSL_CTRL_GET_TLS_EXT_HEARTBEAT_PENDING = 86;

Meta