Constant openssl_sys::SSL_OP_NO_TLSv1_3
pub const SSL_OP_NO_TLSv1_3: c_ulong = 0x20000000;
The portability is definied by:
#[cfg(any(ossl111, libressl340))]
pub const SSL_OP_NO_TLSv1_3: c_ulong = 0x20000000;
#[cfg(any(ossl111, libressl340))]