If I create a snippet for header files like this:
/**
 * @brief ${clsname} is a class that...
 * @namespace ${nsname}
namespace ${nsname}
{
    class ${clsname}
    {
        ${clsname}();
    };
} // namespace ${nsname}

All spaces will disappear in front of the placeholders and I wind up with code looking like this (substituting ${clsname} with MyClass and ${nsname} with mynamespace - leaving the class name and namespace name clamped to the keywords:

/**
 * @brief MyClass is a class that ...
 * @namespace mynamespace
 */
namespacemynamespace
{
    classMyClass
    {
        MyClass();
    };
} // namespacemynamespace


Reproducible: Always

Steps to Reproduce:
1. Create the following snippet:
/**
 * @brief ${clsname} is a class that...
 * @namespace ${nsname}
namespace ${nsname}
{
    class ${clsname}
    {
        ${clsname}();
    };
} // namespace ${nsname}
2. Invoke it and substitute ${clsname} with MyClass and ${nsname} with mynamespace 
3. You get  this:
/**
 * @brief MyClass is a class that ...
 * @namespace mynamespace
 */
namespacemynamespace
{
    classMyClass
    {
        MyClass();
    };
} // namespacemynamespace
Actual Results:  
/**
 * @brief MyClass is a class that ...
 * @namespace mynamespace
 */
namespacemynamespace
{
    classMyClass
    {
        MyClass();
    };
} // namespacemynamespace

Expected Results:  
/**
 * @brief MyClass is a class that ...
 * @namespace mynamespace
 */
namespace mynamespace
{
    class MyClass
    {
        MyClass();
    };
} // namespace mynamespace