External/cxxopts
8
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

default and implicit options in readme

Browse Source 
This closes issue #20.
This commit is contained in:
Jarryd Beck 2016-08-25 08:35:01 +10:00
parent abab8ce325
commit c51b8bbdee
1 changed files with 18 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
README.md
View File

@ -64,6 +64,24 @@ To set up positional arguments, call
where "last" should be the name of an option with a container type, and the where "last" should be the name of an option with a container type, and the
others should have a single value. others should have a single value.
## Default and implicit values
An option can be declared with a default or an implicit value, or both.
A default value is the value that an option takes when it is not specified
on the command line. The following specifies a default value for an option:
cxxopts::value<std::string>()->default_value("value")
An implicit value is the value that an option takes when it is given on the
command line without an argument. The following specifies an implicit value:
cxxopts::value<std::string>()->implicit_value("implicit")
If an option had both, then not specifying it would give the value `"value"`,
writing it on the command line as `--option` would give the value `"implicit"`,
and writing `--option=another` would give it the value `"another"`.
# Linking # Linking
This is a header only library. This is a header only library.