coda_format

A c++17 class for formatting strings.

Examples

cout << format("{0} walked up {1} miles and saw {2}.", "A bear", 20, "an eagle");

using argument methods in different order

format f("{2} saw {0} {1}!");

f.args(20, "eagles"); // inserts {0} and {1}

f.args("A bear"); // inserts {2}

string str = f; // will equal "A bear saw 20 eagles!"

specify type formatting:

format f("{0:f2}", 123.45278);

f.str() == "123.45"; // floating point with precision 2

format f("{0:X}", 10);

f.str() == "0A"; // uppercase hexidecimal

or:

format f("{0,8} h2", "h1");

f.str() == "      h1 h2"; // right aligned spacing

format f("{0,-8:f2} cm", 23.45213);

f.str() == "23.45   cm"; // left aligned spacing

the class will throw invalid_argument exception on errors:

format f("{2} blah"); // throws an exception. no 0 or 1 specifier


format f("{0}", "test", "two"); // throws an exception. missing specifier

Building

After cloning run the following command to initialize submodules:

git submodule update --init --recursive

you can use cmake to generate for the build system of your choice.

mkdir debug; cd debug; 
cmake -DCMAKE_BUILD_TYPE=Debug ..
make
make test

options supported are:

-DENABLE_COVERAGE=ON   :   enable code coverage using lcov
-DENABLE_MEMCHECK=ON    :   enable valgrind memory checking on tests

formatting

I borrowed the feel of composite formating from c#.

basic structure I use here is:

+------------------> opening tag
|    +-------------> width seperator
|    |    +--------> format seperator
|    |    |
{  0 , -8 : F 2 } -> closing tag

   |   |    | |
   |   |    | +----> formating argument, variable length, reserved for future use
   |   |    +------> type of formating, see below
   |   +-----------> width of argument, integer, optional negative sign indicating left align
   +---------------> argument index, integer

format types

• x: lower case hexidecimal
• X: upper case hexidecimal
• o: octal
• f: floating point values
• e: scientific floating point
• E: uppercase scientific floating point

some examples are:

{0,-8}  // left align value with a width of 8
{1,4:X} // align right a hexidecmal value with a width of 4
{2:E}   // scientific floating point

Alternatives

cppformat

boost format

fast format

tiny format