/tmp/ccObgTdP.o: In function `scht::encrypt(std::string)':
scht.cpp:(.text+0xc3): undefined reference to `crypto_box_curve25519xsalsa20poly1305_ref(std::string const&, std::string const&, std::string const&, std::string const&)'
/tmp/ccObgTdP.o: In function `scht::decrypt(std::string)':
scht.cpp:(.text+0x1c7): undefined reference to `crypto_box_curve25519xsalsa20poly1305_ref_open(std::string const&, std::string const&, std::string const&, std::string const&)'
/tmp/ccObgTdP.o: In function `scht::scht()':
scht.cpp:(.text+0x803): undefined reference to `crypto_box_curve25519xsalsa20poly1305_ref_keypair(std::string*)'
collect2: error: ld returned 1 exit status
bash: ./a.out: No such file or directory