I encourage you to indent a message when it conceptually belongs to another message. For example:
A trimmed example of an indented file is shown below:
CPairedMessagesLog< ...>::paired_log DirectoryLog = log.next_paired(); DirectoryLog << "Start parsing directory" << strCurrentDirectory << std::endl; // for each file CPairedMessagesLog< ...>::paired_log FileLog = log.next_paired( 1); FileLog << "Start parsing file" << strCurrentFile << std::endl; // ... code FileLog << "End parsing file" << strCurrentFile << std::endl; DirectoryLog << "End parsing directory" << strCurrentDirectory << std::endl;Note: indenting is done using tabs.