The D Programming Language's Unofficial Docs
beta
The D Programming Language's Unofficial Docs
beta
the type to return
the _input range to read from
the FormatSpec to use when reading from input
A value from input of type T
A FormatException if spec cannot read a type T
Booleans
auto str = "false"; auto spec = singleSpec("%s"); assert(unformatValue!bool(str, spec) == false); str = "1"; spec = singleSpec("%d"); assert(unformatValue!bool(str, spec));
Null values
auto str = "null"; auto spec = singleSpec("%s"); assert(str.unformatValue!(typeof(null))(spec) == null);
Integrals
auto str = "123"; auto spec = singleSpec("%s"); assert(str.unformatValue!int(spec) == 123); str = "ABC"; spec = singleSpec("%X"); assert(str.unformatValue!int(spec) == 2748); str = "11610"; spec = singleSpec("%o"); assert(str.unformatValue!int(spec) == 5000);
Floating point numbers
import std.math : approxEqual; auto str = "123.456"; auto spec = singleSpec("%s"); assert(str.unformatValue!double(spec).approxEqual(123.456));
Character input ranges
1 auto str = "aaa"; 2 auto spec = singleSpec("%s"); 3 assert(str.unformatValue!char(spec) == 'a'); 4 5 // Using a numerical format spec reads a Unicode value from a string 6 str = "65"; 7 spec = singleSpec("%d"); 8 assert(str.unformatValue!char(spec) == 'A'); 9 10 str = "41"; 11 spec = singleSpec("%x"); 12 assert(str.unformatValue!char(spec) == 'A'); 13 14 str = "10003"; 15 spec = singleSpec("%d"); 16 assert(str.unformatValue!dchar(spec) == '✓');
Arrays and static arrays
1 string str = "aaa"; 2 auto spec = singleSpec("%s"); 3 assert(str.unformatValue!(dchar[])(spec) == "aaa"d); 4 5 str = "aaa"; 6 spec = singleSpec("%s"); 7 dchar[3] ret = ['a', 'a', 'a']; 8 assert(str.unformatValue!(dchar[3])(spec) == ret); 9 10 str = "[1, 2, 3, 4]"; 11 spec = singleSpec("%s"); 12 assert(str.unformatValue!(int[])(spec) == [1, 2, 3, 4]); 13 14 str = "[1, 2, 3, 4]"; 15 spec = singleSpec("%s"); 16 int[4] ret2 = [1, 2, 3, 4]; 17 assert(str.unformatValue!(int[4])(spec) == ret2);
Associative arrays
auto str = `["one": 1, "two": 2]`; auto spec = singleSpec("%s"); assert(str.unformatValue!(int[string])(spec) == ["one": 1, "two": 2]);
Reads a value from the given _input range according to spec and returns it as type T.