Enum Crt 

pub enum Crt {
    Static,
    Dll,
}

Which of Microsoft’s two C runtimes a program in the MSVC environment is linked against.

cl.exe spells the choice /MT and /MD, and here it is -fms-runtime-lib=static and -fms-runtime-lib=dll, which is clang’s spelling. Two sets of libraries and two macros: the headers read _MT for both and _DLL only for the second, and that is how a header knows its functions are imported from a DLL rather than linked into the program.

The static one is the default, which is the opposite of cl.exe, and the reason is the machine the program is copied to. The universal CRT is part of Windows 10 and later, but the Visual C++ runtime is not: vcruntime140.dll arrives with the redistributable, and a program linked /MD on a machine that never installed it does not start. A program linked /MT carries both and starts anywhere, which is what the mingw-w64 rows give without being asked.

Variants

Static

/MT: libcmt.lib, libucrt.lib and libvcruntime.lib, all three linked into the program.

Dll

/MD: msvcrt.lib, ucrt.lib and vcruntime.lib, which are import libraries for ucrtbase.dll and vcruntime140.dll with the startup code in the first of them.

Trait Implementations

impl Clone for Crt

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Crt

impl Debug for Crt

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Crt

fn default() -> Self

Returns the “default value” for a type.

impl Eq for Crt

impl PartialEq for Crt

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Crt