build issues with rust < 1.80

[keldonin]

Symptom

It seems that fix #217 created another issue, namely with rust 1.79, and possibly with earlier versions as well. Interstingly enough, 1.66 (MSRV) is not affected.

Example

$ rustup override set 1.79
info: override toolchain for '/home/eric/github/rust-cryptoki' set to '1.79-aarch64-unknown-linux-gnu' 
$ cargo b
   Compiling cryptoki-sys v0.1.8 (/home/eric/github/rust-cryptoki/cryptoki-sys)
   Compiling paste v1.0.14
   Compiling cfg-if v1.0.0
   Compiling zeroize v1.7.0
   Compiling log v0.4.20
   Compiling bitflags v1.3.2
   Compiling libloading v0.7.4
   Compiling secrecy v0.8.0
   Compiling cryptoki v0.7.0 (/home/eric/github/rust-cryptoki/cryptoki)
error[E0425]: cannot find function `size_of` in this scope
   --> cryptoki/src/mechanism/mod.rs:979:33
    |
979 |                 ulParameterLen: size_of::<CK_GCM_PARAMS>()
    |                                 ^^^^^^^ not found in this scope
    |
help: consider importing one of these items
    |
11  + use core::mem::size_of;
    |
11  + use std::mem::size_of;
    |

error[E0425]: cannot find function `size_of` in this scope
    --> cryptoki/src/mechanism/mod.rs:1042:25
     |
1042 |         ulParameterLen: size_of::<T>()
     |                         ^^^^^^^ not found in this scope
     |
help: consider importing one of these items
     |
11   + use core::mem::size_of;
     |
11   + use std::mem::size_of;
     |

error[E0425]: cannot find function `size_of` in this scope
   --> cryptoki/src/object.rs:620:48
    |
620 |             | Attribute::WrapWithTrusted(_) => size_of::<bool>(),
    |                                                ^^^^^^^ not found in this scope
    |
help: consider importing one of these items
    |
5   + use core::mem::size_of;
    |
5   + use std::mem::size_of;
    |

error[E0425]: cannot find function `size_of` in this scope
   --> cryptoki/src/object.rs:623:17
    |
623 |                 size_of::<CK_UTF8CHAR>() * bytes.len()
    |                 ^^^^^^^ not found in this scope
    |
help: consider importing one of these items
    |
5   + use core::mem::size_of;
    |
5   + use std::mem::size_of;
    |

error[E0425]: cannot find function `size_of` in this scope
   --> cryptoki/src/object.rs:627:46
    |
627 |             Attribute::CertificateType(_) => size_of::<CK_CERTIFICATE_TYPE>(),
    |                                              ^^^^^^^ not found in this scope
    |
help: consider importing one of these items
    |
5   + use core::mem::size_of;
    |
5   + use std::mem::size_of;
    |

error[E0425]: cannot find function `size_of` in this scope
   --> cryptoki/src/object.rs:629:36
    |
629 |             Attribute::Class(_) => size_of::<CK_OBJECT_CLASS>(),
    |                                    ^^^^^^^ not found in this scope
    |
help: consider importing one of these items
    |
5   + use core::mem::size_of;
    |
5   + use std::mem::size_of;
    |

error[E0425]: cannot find function `size_of` in this scope
   --> cryptoki/src/object.rs:639:46
    |
639 |             Attribute::KeyGenMechanism(_) => size_of::<CK_MECHANISM_TYPE>(),
    |                                              ^^^^^^^ not found in this scope
    |
help: consider importing one of these items
    |
5   + use core::mem::size_of;
    |
5   + use std::mem::size_of;
    |

error[E0425]: cannot find function `size_of` in this scope
   --> cryptoki/src/object.rs:640:38
    |
640 |             Attribute::KeyType(_) => size_of::<CK_KEY_TYPE>(),
    |                                      ^^^^^^^ not found in this scope
    |
help: consider importing one of these items
    |
5   + use core::mem::size_of;
    |
5   + use std::mem::size_of;
    |

error[E0425]: cannot find function `size_of` in this scope
   --> cryptoki/src/object.rs:642:42
    |
642 |             Attribute::ModulusBits(_) => size_of::<CK_ULONG>(),
    |                                          ^^^^^^^ not found in this scope
    |
help: consider importing one of these items
    |
5   + use core::mem::size_of;
    |
5   + use std::mem::size_of;
    |

error[E0425]: cannot find function `size_of` in this scope
   --> cryptoki/src/object.rs:654:39
    |
654 |             Attribute::ValueLen(_) => size_of::<CK_ULONG>(),
    |                                       ^^^^^^^ not found in this scope
    |
help: consider importing one of these items
    |
5   + use core::mem::size_of;
    |
5   + use std::mem::size_of;
    |

error[E0425]: cannot find function `size_of` in this scope
   --> cryptoki/src/object.rs:655:64
    |
655 |             Attribute::EndDate(_) | Attribute::StartDate(_) => size_of::<CK_DATE>(),
    |                                                                ^^^^^^^ not found in this scope
    |
help: consider importing one of these items
    |
5   + use core::mem::size_of;
    |
5   + use std::mem::size_of;
    |

error[E0425]: cannot find function `size_of` in this scope
   --> cryptoki/src/object.rs:658:17
    |
658 |                 size_of::<CK_MECHANISM_TYPE>() * mechanisms.len()
    |                 ^^^^^^^ not found in this scope
    |
help: consider importing one of these items
    |
5   + use core::mem::size_of;
    |
5   + use std::mem::size_of;
    |

error[E0425]: cannot find function `size_of` in this scope
   --> cryptoki/src/object.rs:770:24
    |
770 |     let as_array: [u8; size_of::<CK_BBOOL>()] = slice.try_into()?;
    |                        ^^^^^^^ not found in this scope
    |
help: consider importing one of these items
    |
5   + use core::mem::size_of;
    |
5   + use std::mem::size_of;
    |

error: unused import: `TryInto`
  --> cryptoki/src/mechanism/mod.rs:14:29
   |
14 | use std::convert::{TryFrom, TryInto};
   |                             ^^^^^^^
   |
note: the lint level is defined here
  --> cryptoki/src/lib.rs:38:8
   |
38 |        unused,
   |        ^^^^^^
   = note: `#[deny(unused_imports)]` implied by `#[deny(unused)]`

For more information about this error, try `rustc --explain E0425`.

Root cause

use std::mem::size_of expressions missing