bslfmt_formatterstring

Detailed Description

Provide a string formatter for use by bsl::format.

Outline

• Purpose
• Classes
• Canonical Header
• Description
  • Usage
    • Example: Formatting a basic string

Purpose

Provide a string formatter for use by bsl::format

Classes

• bsl::formatter<t_CHAR *, t_CHAR>: formatter specialization for t_CHAR *
• bsl::formatter<const t_CHAR *, t_CHAR>: specialization for const t_CHAR *
• bsl::formatter<t_CHAR[N], t_CHAR> : specialization for character arrays
• bsl::formatter<std::basic_string>: formatter for std::basic_string
• bsl::formatter<bsl::basic_string>: formatter for bsl::basic_string
• bsl::formatter<std::basic_string_view>: for std::basic_string_view
• bsl::formatter<bsl::basic_string_view>: for bsl::basic_string_view
• bsl::formatter<bslstl:::StringRefImp<t_CHAR> >: for bslstl:::StringRef

Canonical Header

bsl_format.h

Description

This component provides partial specializations for the bsl::formatter type covering the case for string formatting. Those types meet the requirements as specified in [formatter.requirements] and support all functionality supported by the C++20 std::formatter string type specializations with the following exceptions:

• No support for escaped strings.
• No support for non-C locales.

This header is not intended to be included directly. Please include <bsl_format.h> to be able to use specializations of the bsl::formatter for strings.

Usage

In this section we show the intended use of this component.

Example: Formatting a basic string

We do not expect most users of bsl::format to interact with this type directly and instead use bsl::format or bsl::vformat, so this example is necessarily unrealistic.

Suppose we want to test this formatter's ability to a substring with padding and minimum width.

 bslfmt::MockParseContext<char> mpc("*<5.3s", 1);
 
 bsl::formatter<const char *, char> f;
 mpc.advance_to(f.parse(mpc));
 
 const char *value = "abcdefghij";
 
 bslfmt::MockFormatContext<char> mfc(value, 0, 0);
 
 mfc.advance_to(bsl::as_const(f).format(value, mfc));
 
 assert("abc**" == mfc.finalString());