commit 4de60dde6ed734acbc428887866ae3d528abbd37 (tree) parent 11ca38a4e9c637bf6ff635f4f62634edaf89f853 Author: Andrew Kelley <superjoe30@gmail.com> Date: Tue, 26 Jun 2018 15:48:42 -0400 langref: explicit cast section Diffstat:
| M | doc/langref.html.in | | | 31 | ++++++++++++++++++++++++++++++- |
1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/doc/langref.html.in b/doc/langref.html.in @@ -3602,6 +3602,10 @@ test "implicit cast - invoke a type as a function" { var b = u16(a); } {#code_end#} + <p> + Implicit casts are only allowed when it is completely unambiguous how to get from one type to another, + and the transformation is guaranteed to be safe. + </p> {#header_open|Implicit Cast: Stricter Qualification#} <p> Values which have the same representation at runtime can be cast to increase the strictness @@ -3722,7 +3726,32 @@ test "float widening" { {#header_close#} {#header_open|Explicit Casts#} - <p>TODO</p> + <p> + Explicit casts are performed via {#link|Builtin Functions#}. + Some explicit casts are safe; some are not. + Some explicit casts perform language-level assertions; some do not. + Some explicit casts are no-ops at runtime; some are not. + </p> + <ul> + <li>{#link|@bitCast#} - change type but maintain bit representation</li> + <li>{#link|@alignCast#} - make a pointer have more alignment</li> + <li>{#link|@boolToInt#} - convert true to 1 and false to 0</li> + <li>{#link|@bytesToSlice#} - convert a slice of bytes to a slice of another type</li> + <li>{#link|@enumToInt#} - obtain the integer tag value of an enum or tagged union</li> + <li>{#link|@errSetCast#} - convert to a smaller error set</li> + <li>{#link|@errorToInt#} - obtain the integer value of an error code</li> + <li>{#link|@floatCast#} - convert a larger float to a smaller float</li> + <li>{#link|@floatToInt#} - obtain the integer part of a float value</li> + <li>{#link|@intCast#} - convert between integer types</li> + <li>{#link|@intToEnum#} - obtain an enum value based on its integer tag value</li> + <li>{#link|@intToError#} - obtain an error code based on its integer value</li> + <li>{#link|@intToFloat#} - convert an integer to a float value</li> + <li>{#link|@intToPtr#} - convert an address to a pointer</li> + <li>{#link|@ptrCast#} - convert between pointer types</li> + <li>{#link|@ptrToInt#} - obtain the address of a pointer</li> + <li>{#link|@sliceToBytes#} - convert a slice of anything to a slice of bytes</li> + <li>{#link|@truncate#} - convert between integer types, chopping off bits</li> + </ul> {#header_close#} {#header_open|Peer Type Resolution#}