pw_string#
Efficient, easy, and safe string manipulation
Stable C++17 Code Size Impact: 500 to 1500 bytes
Efficient: No memory allocation, no pointer indirection.
Easy: Use the string API you already know.
Safe: Never worry about buffer overruns or undefined behavior.
Pick three! If you know how to use std::string, just use
pw::InlineString in the same way:
// Create a string from a C-style char array; storage is pre-allocated!
pw::InlineString<16> my_string = "Literally";
// We have some space left, so let's add to the string.
my_string.append('?', 3); // "Literally???"
// Let's try something evil and extend this past its capacity 😈
my_string.append('!', 8);
// Foiled by a crash! No mysterious bugs or undefined behavior.
Need to build up a string? pw::StringBuilder works like
std::ostringstream, but with most of the efficiency and memory benefits
of pw::InlineString:
// Create a pw::StringBuilder with a built-in buffer
pw::StringBuffer<32> my_string_builder = "Is it really this easy?";
// Add to it with idiomatic C++
my_string << " YES!";
// Use it like any other string
PW_LOG_DEBUG("%s", my_string_builder.c_str());
Check out Get Started & Guides for more code samples.
String manipulation on embedded systems can be surprisingly challenging.
C strings? They’re light-weight but come with many pitfalls for those who don’t know the standard library deeply.
C++ strings? STL string classes are safe and easy to use, but they consume way too much code space and are designed to be used with dynamic memory allocation.
Roll your own strings? You don’t have time! You have a product to ship!
Embedded systems need string functionality that is both safe and suitable for resource-constrained platforms.
pw_string provides safe string handling functionality with an API that
closely matches that of std::string, but without dynamic memory
allocation and with a much smaller binary size impact.
Is it right for you?#
pw_string is useful any time you need to handle strings in embedded C++.
If your project written in C, pw_string is not a good fit since we don’t
currently expose a C API.
On the other hand, for larger platforms where code space isn’t in short supply
and dynamic memory allocation isn’t a problem, you may find that std::string
meets your needs.
Tip
pw_string works just as well on larger embedded platforms and host
systems. Using pw_string even when you could get away with std:string
gives you the flexibility to move to smaller platforms later with much less
rework.