Go 1.6 (2016-02-17)

Go 1.6 was released in February 2016, enabling HTTP/2 support by default and enhancing template functionality and runtime detection.

Major Changes

Toolchain

• Vendor: Support for the vendor directory is now enabled by default. The GO15VENDOREXPERIMENT environment variable defaults to 1. Go 1.6 is the last version that allows disabling Vendor support by setting this variable to 0.
• Cgo: Rules for passing Go pointers to C code are now explicitly defined and enforced. As long as C code does not retain pointers to Go-allocated memory, and that memory itself does not contain pointers to other Go-allocated memory, Go code can pass pointers to Go-allocated memory to C. Violating these rules will cause a runtime crash.

Runtime

• Map Concurrency Detection: The runtime added lightweight detection for concurrent misuse of Maps. If a concurrent write operation is detected, the program will crash and print an error message. This helps discover potential data race issues.

Standard Library

• net/http:
  • HTTP/2 Support: The net/http package now supports the HTTP/2 protocol by default (over HTTPS). When using HTTPS, Go clients and servers will automatically negotiate and use HTTP/2. Existing HTTP programs can enjoy the performance benefits of HTTP/2 without code changes.
• text/template and html/template:

  • Whitespace Trimming: Supports using {{- and -}} syntax to trim whitespace around template actions.

    {{23 -}} < {{- 45}} // Output "23<45"

  • Block Action: Introduced the {{block "name" pipeline}}...{{end}} action, allowing template blocks to be defined and subsequently overridden, which is very useful for defining base layout templates.

• sort:
  • Performance Improvement: The implementation of the sort package was rewritten, reducing Less and Swap method calls by about 10%, improving sorting speed. Note that the sort order for equal elements may change (unstable sort).

References

For more details, please refer to the official release notes: Go 1.6 Release Notes